Being a little lazy right now to do the research, does the PS4 software (games) output lossless audio?

Bumpers for a response.

Sorry man I am not sure on this one

seems like there are answers to be found here:
http://www.neogaf.com/forum/showthread.php?t=942898

Thanks.  But it still doesn't answer my question in regards to the games.  Blu-Ray playback, the PS4 supports lossless audio formats.  But are the games encoded with losses audio?  I could make that assumption, but I want to be sure.  Thanks again.

This really depends on a lot of things. Most of the time a games sound effects will be generated randomly and those sounds are almost always lossless. The in game music and voice acting that comes from the Blu-Ray disc will usually be lossless as well, but not always.

Downloaded games may or may not have the lossless audio. If there is a size difference between the downloaded version and the size on disc than the downloaded version will likely be limited to Dolby 5.1. However, if the game is bit-for-bit the same size downloaded and on disc, then the downloaded one will have lossless audio.

If the game you are playing is a small indie game you will almost never have lossless audio since most indie games don't have the capital for high end audio mastering. 

So the answer is all of the following, Yes, No, Sometimes, and Maybe.

That DOES help.  I don't plan on upgrading both my TV and a/v receiver soon.  So I'm trying to pre-configure my set up as I "make do" with what I have.  My receiver will encode and pass thru lossess audio, but it will NOT pass thru 3D signals.  Running both the PS3 and PS4 Pro to my receiver and running my receiver to my television will garrantee the best audio quality.  But my biggest concern is the PS4 Pro downsampling when the video signal goes from the PS4 Pro to the a/v receiver.  Will that downsampling be lost because of an older a/v receiver?  More than likely, this will be within the HDMI bandwith (1.4 version I think) so I should be able to take advantage of the downsampling.  If not, I'll have to run the PS4 Pro straight to the televsion and run my audio via ARC to the a/v receiver.  But then, I'll lose lossless audio since ARC doesn't support it.  Then there's the issue of "which console will server as my Blu-Ray player."  I'll just assume "worse" case scenario for now.  Thanks.

It looks like you already have it figured out but yes, the PS4 supports Linear PCM over HDMI for Games and Apps like Netflix. It also supports formats like Dolby and DTS if your system is too old to support Linear PCM so you should get the best sound going from PS4 -> Reciever -> TV no matter the situation.

This is a very different question. Of course individual Games will be encoded at different bitrates and with different formats , but the PS4 can output all softwares Audio lossless through HDMI Linear PCM, that is the PS4 does not need to "Decode" the track and can just pass along whatever is there, be it a stereo , Dolby, or LCPM track.  This is in contrast to say using an optical cable, which cannot pass over lossless audio regardless of the sources bitrate or encoding format.  

If your system is HDMI 1.4 there is a 99% chance your system supports LCPM 5.1 or even 7.1 , so regardless of the individual games audio you could just leave it on that and you will get the best audio possible from each piece of software. There really is not anyway to tell from a games box or specs page what type of Audio encoding it has sadly, the most you will get is "5.1" which tells you nothing. 

Yes.  It is a 7.1 system and it supports Dolby True HD and DTS-HD Master Audio.  But this Receiver was made in 2008.  I was afraid that any graphical enhancements by a PS4 Pro to a 1080p television would be lost going through a receiver this old.  I might have to buy a new one if that's the case.