I believe that the RX480 will hard launch at E3. AMD likes doing this, it's a great way of getting their name out, with EA's help.
On the other hand. I don't think AMD had the resources to release various chips at the same time, Polaris was probably a big bullet to bite on alone.
For the last several years they haven't changed their architecture or released new lines of products whatsoever.
Sure, there are a few "upgraded" APU's and Athlons, and FIJI.... but that's it. With Polaris, AMD secured 4 massive deals that have given them a cash infusion.
AMD could not have foreseen that. This means quite a bit, not all of it good for PC gamers:
- Not including discrete cards, 14nm GPU chips are being put into the new AND "refreshed" versions of the PS4/Xbone, the new Macbook Pro's, the new iMac's, various OEM builders, chinese super-computers.
- They couldn't have released the product earlier because of this ramp up in production due to point #1
- Zen is coming, but it's also 14nm, and it uses the same avenues of production as Polaris
- the first 14nm chips HAD to have good yields, so they went with a smaller die. Imagine securing these deals with all these big companies and finding out 50% of your chips were worthless? They would be functionally broke
Because of this, you can see why AMD has done what it's done. Polaris was more important from a securing funding standpoint. They'll use this profit to advance and enhance Zen and Vega. Both of which will most likely launch at the end of this year. This is huge, AMD actually has its first chance to be profitable in the long-term in a while.
Imagine an APU with 4 Zen cores functionally equivalent to an i7 4900m, with graphics on-par with a desktop 370x? That's fantastic.