According to "Bloomberg Sources" because of component and logistics constraints Sony have had to reduce their planned production of 16m PS5 units this fiscal year to 15m units this fiscal year.

They're shipment forecast for the fiscal year has been 14.8m and they haven't adjusted this figure yet. Though with a production target of 15m that makes shipping 14.8m challenging.

Issues continue to affect hardware manufacturing and shipping for everyone.

Sony Cuts PlayStation 5 Production on Chips Shortage - Bloomberg

If they produce 15 million then its likely the shipment number may end up being a bit below their forecast.

If you're working at SNY right now you gotta be totally bummed. Knowing full well they should've far out produced PS4, while easily selling every last PS5 has got to be aggravating. It'll be even worse if things do get back to the old normal and a relatively hard shift happens away from indoor activities to outdoor. PS5 sales would likely suffer from that point forward, and knowing you could've made those sales if you only had the units available sooner would suck.
Now if a shift doesn't happen, or it's soft, then they can at least feel comfortable knowing that worst case, they've got another PS4 on their hands. If things don't really change, yet the shortages get solved, year 3 and 4 sales will likely reach unfathomable heights.

 When did Sony increase the figure to 16 million for FY 2021 I cannot find any official source for that 16 million figure ?

The 16m is a reported production target, not shipments. Neither the 16m or 15m production figure are official from Sony, Bloomberg sources only. 14.8m shipment forecast is an official figure.

That's where the confusion is we have two production figures the one that's  been around ages of 15 million and now this 16 million figure, and without any verification the later just appears to be there to serve the story.

There is a difference between production and shipment. Units that got produced in the last weeks of the year may only get shipped in January.

There is no "shipped" in a fq/fj report. If a console reaches the end of the assembly line at Dec 31st 11:59pm, it is accounted for. If it is already sold, it goes into the table as sold product, if it isn't sold, it goes into stock inventory products.

Yes, you can increase or decrease those game sales to some degree, but you will only sell so many games per unit. Beyond that point, you need to sell more units if you want to sell more games.

The Merovingian also saw no reason to give up the Keymaker, and Morpheus knew the war should now be over, but how did that play out? I wouldn't suggest living in a bubble because bubbles eventually pop.

Just pointing out some possibilities. Who knows what'll happen? Perhaps consult the Oracle?

My post had nothing to do with shipped numbers both those 15 and 16 million numbers are production forecasts, I was questioning the veracity of the article and while the 15 million may be questionable it at least has been used by many outlets in relation to a 14.8 million shipped forecast, I cannot find any similar reporting of the 16 million number so I'm sceptical especially in light of previous Bloomberg claims like this. https://www.gamesindustry.biz/articles/2020-09-15-sony-reportedly-cuts-ps5-production-by-4m-units