By the time a lot of us are able to take delivery of our Model Y (either this month, or possibly in Sept or could be Oct), and then waiting another month for plates to come in from CA DMV before we can finally apply for a new HOV decal, I wouldn't doubt that our application and checks will get processed sometime in January or February 2022.
But hey, at least we'll probably get the last decal made available to use for the next few years before this program sunsets on Sept 2025.
I haven't done the math, but maybe there's an advantage in delaying your application so that you get the maximum length of time on new stickers?
I think mine (blue) expire January 2024?
As you stated, the entire HOV sticker program is supposed to end (after several extensions) in 2025. People have speculated on this Forum whether it will even be extended again by the California Legislature, since BEVs appear to be "winning" and sales may increase dramatically with the new pickups (Cybertruck, Rivian, Ford) and long-range road cars. (Looking in my crystal ball, I see huge traffic jams of BEVs crammed into Bay Area HOV lanes during commuter hours. Ha, ha.) Maybe HOV stickers will eventually have to be limited to just solar-powered vehicles (like the Aptera) only?
Anyway, perhaps next year's stickers (what color?) will last until the final end?