I think no T rudders for a couple of editions, because as I said, the performance gap would be too large with all the other boats.I doubt that adding more speed is the answer to the concerns about boats constantly crashing into waves. Yes you are faster but that only means that the crash is even harder.
So far nobody got injured.So far nobody got injured too badly.
I think the foilers need more control. T-rudders are the usual answer but Malizia shows that there is still a lot of mileage left in the hull design.
The next set of rules -AFAIK voted on after the finish of the next VG- will be interesting. Do we see t-rudders? Or perhaps the return of additional appendages, say some form of trim tab?
Then there is the potential elephant in the room. Two new boats in the next VG are without foils. If their gamble plays out things will change again.
Also, imagine rocketing down a wave, foil's out, T foil lifts you up fully out the water, all the sudden you're going 40 knots into a wall of water ahead. Even with a Malizia hull shape, that's a pretty brutal hit. T foils work wonders in flat waters, remain to be proven in any sizeable waves.