re: Poker & HM2 released this week
They haven't specified a HM1 cutoff, only that it will be barely maintained. Only major bug fixes and site compatibility fixes going forward, but they don't say for how long. It won't get any new stats, features, enhancements, etc. Probably no new sites/networks that come online from now on either.
If you upgrade to HM2, you lose your HM1 activation after 6 months (was 90 days but they extended it due to outrage from new upgraders wanting to go back). They also said they will switch you back and forth between HM1 and HM2 licenses upon request, but you can't have both active at once. A bit silly and unnecessary IMO, but that's the decision they made. My guess is simply to keep a handle on the number of active licenses they have to potentially support, and to wind down the HM1 support requests.