Microsoft started releasing several games on the Switch in 2019 including Ori and the Blind Forest.  They started releasing games on Playstation not long afterward.  Sony started releasing games on the PC in 2020 such as Horizon Zero Dawn.  Microsoft started the multiplatform initiative in 2019 and Sony followed their lead in 2020.

(This is ignoring one-off cases like Minecraft and Helldivers which were released on other platforms several years earlier.)

I'm missing something. What games MS released on PS in 2019 ? Helldivers has always been a PC/PS game.

Can they? Obviously. There's no technical obstacles preventing their games from being ported to PlayStation.

Will they? It's certainly possible. It just depends on whether they decide it makes good business sense. In other words, do they think they stand to gain more from trying to potentially maximize software sales by having their games available on as many platforms as possible than they stand to lose from potentially sacrificing hardware sales in the process?

I could see a scenario where they straddle the line between first-party and third-party, releasing games on PlayStation & Switch as well as PC while still offering Xbox hardware to people who just really like Xbox systems. Xbox as a console brand is essentially stuck in a distant third place, a position it will likely be unable to extricate itself from, which puts a limit on their software's sales potential. It's been well-established that Xbox hardware, like many consoles throughout gaming history, is a loss leader, having never generated a profit. MS is already porting several games to other systems, which I think is them testing the waters. If it works out, I think they'll continue to port more games. It would not surprise me at all if we even see marquee franchises like Halo and Gears on PlayStation before the decade is out. If that does happen, I personally would seriously consider not buying Xbox systems anymore and just sticking with Nintendo & PlayStation, which would be the first time I wouldn't own an Xbox system (though if MS forces digital-only for the next generation of Xbox, they're not getting my support anyway).

The point was to expand into the mobile market with owning Candy Crush and Call of Duty Mobile, as well as adding more content to Game Pass to help grow the service. Call of Duty day 1 on Game Pass will likely add millions of new subs.

Selling the most consoles isn't Xbox's goal anymore, but is to expand the Xbox business into as many places as possible, which is why they release all games day 1 on PC now. They are also likely going to release an Xbox store on mobile platforms. Microsoft CEO wants Xbox to be as profitable its other divisions and with the Activision Blizzard deal, Xbox is now bigger than Windows in terms of revenue.

At this point I think Microsoft/Xbox is fine with selling ~50 million consoles per generation as long as they grow in other markets outside of console gaming.

An article that could interest you : https://www.theverge.com/2024/4/5/24122208/microsoft-xbox-kareem-choudhry-leaving-xbox-cloud-gaming

"This latest Xbox shake-up comes as Microsoft continues to consider strategy changes for its Microsoft Gaming division. Earlier this year, Microsoft placed a number of previously Xbox-exclusive games on PS5 and Nintendo Switch, with Sea of Thieves set to launch on Sony’s console on April 30th.

Sources familiar with Microsoft’s plans tell me that the company continues to evaluate other Xbox-exclusive games coming to PS5. I understand Sea of Thieves will be a key test for whether other games might make their way to PS5 or Nintendo Switch."

It would be funny to play Gears 4/5 on Switch 2 on the go.

Do you truly believe that Xbox Series will sell 50m? Because I see almost 0 chance of that happening; and if their next console is just a traditional console (but this time with less exclusives than ever) I think it will sell just as much as the Wii U.

Not impossible if the $$$ is right.

I think Gears 5 on Switch 2 would be fun to play.

Yes they could and I believe that is what they are experiementing with doing with releasing a few Xbox exclusives to playstation and see how that goes.