I would expect this. They'll likely have nothing added (outside of F&F) during this time- call it April 2018-2019.
I find it improbable that HP will be done by April 2019- and with the expected post potter rush + SW rush that is going to skyrocket from late 2019 and beyond- this makes perfect sense.
What I would wager on, baring an economic meltdown, is that this offer won't ever present itself again in the near future.
ETA:
@JoeCamel I just called and they said to go to the park and that they should be able to do it there for you. I'm sure it's still YMMV, but I certainly can sell better in person- so I'm gonna try and swing it when I'm there next week. Mine is
way later too- I got APs in September but upgraded to Power in December. So I'm not expecting it, but I'll let you know either way.