Xbox without Halo is pretty impressive.
Total market for PS/XB has remained fairly steady. By VGC numbers we have 182M Gen 6, 173M Gen 7, and 162.5M Gen 8, which will continue accumulate over the next 2 years (PS4 should have >10M left in the tank by itself), so we'll see gen 8 end at 175-180M as well.
Premise for Gen 9 LTD performance should start with this baseline. Did either party do anything to expand the base? For PS5, despite the obvious hype right now, answer seems like a no. When you zoom out, PS5 is more of the same, though that shouldn't be seen as a slight - Sony's been the market king for 25 years, makes sense to continue a successful strategy with refinement.
HOWEVER I do think this gen yields room for a little expansion on the 180M base, because Microsoft has taken two actions - frugal alternative at launch and aggressive stance with Gamepass, and on top of that, these two ideas synergize very well (see their $25/$35 monthly pricing strategy). I think this combined strat is the first true effort between the two to expand the buying base, instead of implementing tactics to eat into each other's market share.
I expect this gen to crack 200M between the two, with Sony hitting the same ballpark as last gen (PS5 LTD @ 125M, +/- 10M), but Xbox expanding from their 45-50M range up to 70M (+/- 10M) or so. Final result of 130M PS5 / 70M XBS would not surprise me, come 2028.