I think it's my answer that has been misunderstood, you're questioning whether 2v2 will be ignored like 5v5 is on live, but I don't think you need to worry really, the highest rating you have will provide you with the highest ilvl, now what we dont know is if you can only get the highest ilvl gear from playing the bracket that has the highest rating or if u can still get that ilvl piece on other brackets.
If option A, you only get the ilvl by playing the bracket of your highest current rating , example : your 2v2 is 1800 rating and your 3v3 is 2600 rating, if you only play 2v2 this week you will get 1800 ilvl gear instead of 2600 ( this seems unlikely to me tbh ).
If option B, you get ilvl by playing any bracket and your ilvl reward is based on your highest current rating on any, this would make more sense since that would also explain how you get ilvl gear in bgs, here's an example : fred has 1700 in 2v2 and 1500 in 3v3, fred played a bg at the day of the reset and got a box, fred's box will contain which ilvl ? if option A, it means bg has a fixed ilvl system outside of ranked, which seems weird tbh.
If option B fred will get a box from said BG and in that box fred will have 1700 ilvl gear which makes more sense.
So either way the morale of the story is, don't worry about your precious 2v2 bracket it will always exist because it is the easiest to get into and requires less people