Was there really such a negative feedback?
To be fair to AW, yes there was because they'd announce a product for 'end of the year', and it wouldn't appear for another couple of years. In fact some products announced 5 years ago still haven't materialised, and likely never will (eg: Archmage).
I agree with them, they should only announce a product when it has a fairly firm market date. If it slips a couple of months no-one will complain, but in the past they seemed to announce ideas, rather than products, and they slipped by years, or even never materialised.
That said, I think this policy is being used as a smokescreen here. They could certainly announce that they will/won't be creating more Arena specific products or not. Then again again - my belief is that they won't make more, and commercially it's better for them to say nothing, than say that. So read into the lack of announcements what you will...