Yes, I agree. The M1 MBA and MBPs are not currently eligible for Apple trade-in.* Eligible is the keyword, but I'm not sure about the timing (although I think you're correct). I agree with others here that Swappa, or Mac of all trades (MacMeAnOffer.com), or CashForYourMac.com are reputable places many MR members have used with success, and these places will often take devices in trade (or selling outright at Swappa) before they become eligible for Apple trade-in.I don't believe you will be able to trade in a M1 MBP or MBA as Apple only allows that when a new model of those same machines has been released. I could be wrong
Your best bet is to use Swappa for a private sale.
* You can check the eligibility by going to Apple's trade-in site, entering the serial number, and viewing whether the model you want to trade appears on the list. As of today neither M1 is on the list.