Agreed. I don't necessarily think the phrase of "striking while the iron is hot" works with this line. Of course, now that we've got a taste of a high quality 1/6 '66 villain (Joker), many want more and now, especially with the teasers we've seen. However, the ppl who want these figures will more than likely buy them whenever they're revealed. Like you said, you've (and most likely others) have waited decades for these figures, and if it wasn't for MarsToys, folks would still be waiting/hoping that a company would be interested in making these guys.
If you only want them b/c they're the new and exciting thing but your interest wanes so quickly when it's not revealed fast enough for you, then did you really want them at all? Mars has obviously been working on multiple things behind the scenes that they didn't show us teasers for which I think is fine. I mean, look how long it took '89 Mob Joker to go from sculpt teaser to actually being put up for PO. Classic lines like these are timeless. The only possible issue is the ppl who like these versions of the characters literally dying off