And yet, when playing Jolene Knottley, I just saw that Beardo didn’t work. (I was quite happy, her hero power is to copy a spell from my hand and discount it; I had only a single spell, Ferocious Howl, so with Beardo that could have gone on for quite a while, refilled Jolene’s hand completely, and given her a huge load of armor, but I was still surprised).
Replay link: https://hsreplay.net/replay/QJNM3mMKtynDS54XAy2koZ#turn=7b
Note that not refreshing the hero power is NOT just a visual bug by hsreplay; I saw no refreshed hero power in the game itself either (didn’t think to make a screenshot at a time). So playing the minion was not a misplay on Jolene’s part, she had no other option b/c the hero power didn’t refresh after casting the spell.
I've also observed this personally, and other sources seem to corroborate the fact that adventure bosses can't benefit from cards that refresh hero powers. While undocumented, that aspect seems to be intentional. However, it appears that whoever designed Jolene's deck forgot about it, and gave her a card she cannot use.
https://us.forums.blizzard.com/en/hearthstone/t/auctionmaster-beardo-not-working-in-solo-adventure/21540
I've also observed this personally, and other sources seem to corroborate the fact that adventure bosses can't benefit from cards that refresh hero powers. While undocumented, that aspect seems to be intentional. However, it appears that whoever designed Jolene's deck forgot about it, and gave her a card she cannot use.