I don't think the focus should be about 'beating the PS5 event" necessarily; I thought the Sony event was great but it honestly wouldn't take much from them to at least hit the same level imo. Have a Halo Infinite gameplay demo similar to what Ratchet & Clank had, show a couple of brand new exclusives from your studios and partners, some new third party games, show the value of gamepass and backwards compatibility, and i'd say it's all set.
The difference is that the PS5 event had a lot of wow factor because of it being the first time we were seeing any PS5 games from Sony and even the console itself, whereas Microsoft has already done a lot of that but instead of having it all in one event they spread it out overtime to have a continuous stream of news. We already know what the Series X looks like and know a lot of the exclusive games for it so far: Halo Infinite, Hellblade 2, Project Mara, Everwild, Scorn, The Medium, etc. Perhaps if all of these had been announced for the first time in one event instead of spread out some would say that already matched or surpassed it, but you already know some people see these as non-surprising things now and will use that against it, which is pretty unfair but it is what it is.
But what I think they need to do overall is to show every first party game or partnered game they possibly can at this event, and I mean literally every one that is in any good possible state to be shown. I know Phil Spencer has said previously that he doesn't want to show games too far in advance, but they're not really in a position to be able to hold anything close to their chest right now. The Xbox One got hammered this entire gen for not having any real noticeable big first party presence for majority of its lifecycle, especially in comparison to Sony and Nintendo's incredible first party offerings, and they can't afford the same "Xbox has no games" narrative for the Series X, they need to crush that right out of the gate. Sony and Nintendo both have earned the luxury of not having to reveal everything because they've shown that they will not only deliver games but excellent games at that, their fans know they can expect it, Xbox has to prove this themselves now. I'm not saying show a CG trailer for example something like Compulsion's next game or something that could be 3-4 years out, by all means I don't expect every first party studio to be there, but just anything that is in any presentable state.
