PS5 indeed will run PS4 games more than 100 titles up to 4000 title plus enhancemnet with better resolution, or frame rates (possibly better loading time or maybe some graphic visual enhancement)

[DonFerrari]

BraLoD said:

sales2099 said:

This is essentially where Ms was in 2015, where they did a steady stream of adding titles to the BC list after the initial batch. 

It's writen in the OP almost all 4000 titles will work.

It has nothing to do with how MS handled it back then, its how they are handling it now.

It's full BC from the get go (regarding last gen).

The only part about the 100 is that from the top 100 played on boosted mode almost all were already working.

So the most comparison to 2015 MS that could be done is that the performance boost may be limited to a selection of games at launch.