Looking at the timing, and human nature, I think this is untrue.
I think Devs always regretted the decision to add classes to 1* / 2* heroes.
I think the poll, and the discussion among staff before the winter break, allowed a lower guilt threshold for a decision they had made months ago, but felt bad about actually implementing.
Devs have added a trickle of 3* heroes to gem summons because they discovered players will spend gems to pull Melia, Hisan, Rudolph, etc.
This generates money for SGG.
Activities for 1* / 2* heroes do not generate money for SGG.
In the end, this is a business.
Hopefully Zynga has not bought out the two clones, since new competitors must use innovation to get market share from SGG.