Must...... Resist..... Urge..................

No it can't be updated via a firmware update. UHD uses 33gb per layer, while regular blu ray only uses 25gb per layer. The drives themselves are different, the best a PS4 could do is upscaling rregular blu ray discs to 4k. Like many players of €200- do. 

Thanks, yeah, given BDXL hardware there just needs to be driver support including DRM which has licencing etc,
but especially given this is Sony we're talking that is really just a decision of theirs to make, not really BOM cost per se.
And the open question is will the drive Sony included be able to be flashed to support 4K (and if so, will PS software allow 4k Blu-Ray).
Thing is I read one of their execs saying "it was not possible to be patched" which IMHO only makes sense if it is not BDXL...
I guess people will be looking into that, if it is BDXL, I imagine people will be pulling the drives and trying to flash them etc.

Honestly looking for comparison drives, it's really hard to find good comparisons, because what is on the market for consumers
just tends to include these features at this point, because the extra capability is so cheap, it's hard to find a BR without them.
In fact my comparison drives I used were off, because they were actually both including write capability (if only for regular DVDs).
Which I guess underlines the point it would be cheap for Sony, if in the consumer market nobody bothers to sell a non-BDXL.

I'm thinking Sony signed a deal with Netflix in regards to exclusive 4k content in order to funnel users onto that format.... There is really no other explanation considering Sony JUMPED on DVD with the PS2 and JUMPED on blu ray with the PS3 and the fact that they are killing it this generation whilst MS is selling poorly(in comparison) and yet they included a 4k player in the Xbox One S.

Sony have proven time and time again that they don't really mind spending money on trivial items. The light strip and capacitive power and eject buttons on the launch PS4, the 4 USB ports and various card readers on the OG PS3. Firewire and USB ports on the original PS2. These all could have been omitted, reducing the cost of the console to product and yet they were present. The omission of an UHD blu ray player is baffling considering the cost over a standard blu ray drive is minimal. They even threw in a third USB port in the rear of the PS4 Pro and kept the optical port and light bar so this is quite perplexing.

Ok lets look at the last couple of years:

1. Xmas being touted as the most important time of the year for console sales (according to MS)
2. MS being totally open to reducing their console significantly at Xmas to get sales. Upto $100 when taking into account store credit etc.

Now based on the fact that Sony cannot afford to get into a price war, consider they have created a slim which will most likely give them more profit, by not including a drive says even more money. It's stupid to think a company is milking it because they want to make a profit and not a loss, and money wise they cannot compete with MS in the price reductions.

So imho Sony are making sure they have enough wiggle room to fight MS at Xmas with price cuts/bundles and give them the chance of reducing the price overall quicker if they need to. This reminds me of the XB360 and PS3 battle, Sony had very little room to reduce the price because the components were expensive, now I see the exact opposite.

I think the 4k Blu-ray drive is maybe the difference between PS4 Pro making a slight profit/breaking even versus them making a slight loss at a $399 price point.

I don't think MS is making a loss with One S but that they would be making more profit without the 4k Blu-ray drive ;)

Sony is milking it.

Where have you got your extensive breakdown of costs per machine, would love to see your workings out. ;)

Also I'm guessing you are suggesting that companies all lose money making stuff then, and not trying to break even/make a profit?

Okay, so UHD has more gb per layer. What's your point?  They also have different capacity DVDs that can be read by the same DVD lasers (DVD-5, DVD-9).  Still based on the same technology and we have retro bluray drives that are patch able to UHD. There is no supporting evidence I've ever seen up to this point that suggests the PS4 disc reader is not patchable for 4K content.

Its hard to state something as a fact without giving yourself some credence, Sony themselves haven't denied it, they tip toed around the subject which to me means there's other factors at play. If it wasn't possible, I imagine they'd be inclined to admit that now or at some point in the very near future given the backlash.

I wrote this before but I think Sony signed an exclusive deal with Netflix(ie Netflix paid them alot of money) to funnel users to the format. Sony also saved themselves money by not installing a native UHD player(whether the standard blu ray drive can be converted into an UHD player via firmware is yet to be seen) so in Sony's eyes it was win-win. Now I have no proof to back this up at all, just a thought. They were plugging Netflix during the reveal and a Netflix executive revealed a 4k variant of the PS4 some years back:

https://gamerant.com/netflix-ps4-xbox-one-4k-release/

I think there is something more at play here....