Welp, I just bought the CSC and did it anyway so whatever! I guess we can lock that.

If the username is up for grabs, there will be a banner at the top of their profile that says "This account is inactive. You can Change your Username to it!" If the account will be clearing soon, it'll say "This account will be eligible for clearing on [date] at 3:00 PM"

If neither of those banners show up, the username isn't up for grabs for at least another 3 months or longer (the eligible for clearing banner shows up at 10 months inactive, and the username is available after a year)

Thanks; I'm glad I asked before I picked the name totem!

Yes there is no way to hide the clearing banners. Also make sure a name you want isn't a deceased users account. Those names never get reused. I myself saw a few I liked then saw the banner saying its a deceased users account.

Thankfully the backup name I'm considering just seems to be inactive, not deceased.