It doesn't work that way unfortunately, as the ultra chip always comes later. Apple never releases the ultra chip along with the base chip. The other way would be to first release an M5 Max version only of the Mac Studio, but that would never happen.Maybe not exactly, but it's quite conceivable that an M4 Max/Ultra Studio is released in June 2025 and a new M5 MacBook Pro in Sep/Oct/Nov 2025.
I would actually prefer Apple to delay the next Mac Studio to Sep-Nov 2025 and make it M5 than release an M4 in June. The 9 month lag with the previous SoC seems unnecessary. If they can't release both Max & Ultra at the same time, then just split these into 2 releases. Far more people are likely to buy a Studio Max if it were available than the Ultra version, which probably appeals more to professionals with a much longer refresh cycle.