They are about to either change the game or it will be nothing. I think the former, but just speculating, and I'm not saying whether their plan will work or not, or that it will be either good or terrible, but I think it will be a plan.
I think the reason for the "delay" in squashing the rumors is quite clear - they were planning to announce this strategy change later (remember their initial response was to leak that they would be making a presentation in the Spring). The mass pant wetting from Xbox fanboys and the gleeful but premature grave dancing from the Sony fanboys has brought that forward, but they still want to do a proper job and not blow it (as they have in the past) so have had some work to do. I'd say that means only one thing - they view this as an important moment that they need to get right.
The only things that I am fairly confident of are that they aren't going third party, aren't quitting the industry and they aren't putting major Xbox exclusives day one on PlayStation unless Sony reciprocates (which there is literally no chance of, sadly) or allows Game Pass (which is ever so slightly more possible, but still highly unlikely). One thing I really hope happens is Microsoft reduces its involvement with these online personality lunatics.
It could also be this has made their succession planning timing go off the rails, if the plan was Phil Spencer was handing over to Sarah Bond in the spring and they wanted her to announce her own vision at that moment. I might be saying that because I'm in the exact same position at the moment (on a smaller scale admittedly lol) - stepping down from my role to do something else, but only the board knows for the time being and we're trying to plan for minimal disruption and to allow the next person to hit the ground running.
I think they'll announce timing when they feel they've nailed it and not before. Wouldn't be surprised if they just drop it without warning too.