This is just wishful thinking on my part and will probably never happen, but it would be cool if they continued from the hesei series with an adult Godzilla Junior. If they are to bring back a heroic Godzilla, this would make the most sense since junior was raised with humans as a baby. It would also be nice to see Miki Sagousa back.
Unfortunately, I don't think Toho will allow the filmmakers to take their time. Toho is always famous for their rushed production schedule and small budget for their films and I don't think that's every going to change. Even with Shin Godzilla Higuchi and Anno were under enormous pressure to get the film finished because of the small production schedule and limited budget. I don't remember the exact amount, but I think Shin Godzilla had a very small budget, even smaller than most of the millennium films.