The question is pretty straight-forward. I did not play hs at all during the last two expansions. Is there any way I could get the cosmetics from these expansions' reward tracks? I know there's no way to buy them now. However, since I'd not played the game for quite a while last year, I wonder, if there have been cases of old reward tracks' cosmetics coming back in the store at all.
I don't think any have been offered yet. I hope they do end up offering them as well. I'd say it is pretty likely considering they made old store portraits purchasable with gold. Also some of the pre-purchase exclusive portraits were made available to buy for USD. I'd guess they will be purchasable with gold in a few years since there are so many it would clutter the shop.
No, once the rewards track is gone, you cannot obtain the cosmetics on it anymore, even if you purchased the Tavern Pass. Gotta love FOMO!
That said though, they've offered items from prior rewards tracks in the shop before - in fact, 2 of the skins in the shop right now (Shardseeker Xyrella and Young Rokara) are former Tavern Pass skins, and they can be purchased with Gold.
They're like 99% available sometime in the future (even if Blizzard says otherwise). Because at the end of the day it's a game to collect stuff and people are willing to pay money to collect the stuff. And in the far future for potential new whaling player seeing a collection of class Skins with like "1/70 collected" and knowing they'll never be able to complete that is bad business for Blizzard. So they'll probably make it more accessible to buy or craft older skins for newer player I think. Probably a system like Valorant has (which they already use except the Night Market) or make more skins craftable.