Grubb said the showcase that's being planned was originally meant for last year around TGS time but it fell apart due to partners not being ready (I assume some of their own studios weren't too). The one coming in may/june is supposed to be pretty big and focusing on the next "phase" of ps5 so probably the next 2+ years.If Sony is doing an exclusive FF16 state of play now then its unlikely they do a big main state of play in May/June. They now pretty much have no reason to do their next big SoP until August/Sept. Kind of disappointing as I hoped Sony and Nintendo would do a big one along side all the other shows in beginning of June. Looks like we are getting another summer of scattered events.
Nintendo will probably do it in July/August/Sept. That is probably where they start teasing Switch 2.
If anything I think FF16 getting a big focus now means at most there will be a brief trailer on the showcase to get people ready for the launch of the game a few weeks later and focus will shift to FF7 Rebirth since it's due out early next year. There's not many opportunities to show that game between now and then.