Your memory serves you well. While they didn't say "We promise" or "We guarantee" regarding holiday events, they did state that they would be coming. Life Day was specifically references. And I agree - if we're just getting a half-hearted Christmas offering with the "Life Day" misapplied, I'd rather get nothing at all. Heck, you'd think if they were going to apply all these unnecessary allusions to Christmas, they could at least get into the spirit of giving.
I actually thought the Devs said that nothing relating to real world holidays were planned, and that if they had holidays it would be relevant to the universe/lore, but don't remember them saying it was a guarantee to be in, either. Just something that may come to pass if they felt like doing it (and got the necessary
Also, the worst part is that Life Day isn't even the Star Wars version of Christmas - it's equivalent is Thanksgiving.