Profile pictures should revert to default if Nitro is cancelled

I had Nitro for free for three months thanks to a promotion. During this time, on one server I changed my profile picture. At no point was I warned that if my Nitro ran out, I would never be able to change it again. I assumed that it would revert to my default profile picture as that seems like the most logical thing to happen. It did not and I can't change it.

I assumed this was a bug and made a ticket but was informed that no, this was not a bug, that in order for my profile picture to go back to my default account one I would need to do it manually (ie. pay £9 to get Nitro for no other reason than to change my picture back).

My feedback is that upon a Nitro subscription ending, profile pictures for all servers should automatically be reset to default. At the VERY LEAST if that is not possible, people should be warned that if they don't fix pictures before Nitro running out, they will never be able to change it again without paying). However, it seems mad to me that I need to pay extra money in order to be able to do something (changing profile picture for ALL servers) that free accounts can do.