Overwatch is still popular, not as popular as its peak - But they are also working on Overwatch 2.
I also am on the fence on these for similar reasons. But I have gambled on some at 50%, I would definitely armsweep at 70%.
They have 6 new sets coming out in 2020, and just dropped a few more in Oct, so the theme can't be doing atrociously. I'll buy them before I buy TLM2 at 50% off, that's for sure
On a side note, I don't know what the WoW rights situation is currently, Mega Bloks had sets a few years back, but I wonder if this Blizz/LEGO marriage will eventually lead to WoW sets. It's been rumored.