Please do "Open preorders" for new releases
For each new major release please do a limited time open pre order. It may take longer to service customers but people would be happy to wait rather than miss out entirely.
Whether The Pokemon Company makes money from selling 3M ETBs from Rivals vs 1M ETBs from 3 different sets, what's it matter? Don't release a new set until you are mostly through fulfilling orders, or do a blended production. (Obviously sale numbers are not to scale)
This would help stabilise the TCG game. This won't impact actual collectors and it won't impact players.
Why? Because they can't get their hands on new sets anyway, so it doesn't matter if time between sets is longer. At least this way they can obtain products from the new sets, even if they have to wait, at regular retail prices. AND TPC can make $$$ from every set, instead of just $ per set due to less production. Win win.