I think that this should happen so that other scratch users can get a bigger chance of getting the username they really want because if you look at some cool name snipes like @salsa and @memes and other stuff they havent been on for like 10 years and dont have a project

when I first joined I wanted the username @salsa but it was taken

No support:

1. What if someone is honestly inactive for 2 years and wants to come back? Maybe they forgot about Scratch but remembered about it and decided to continue from where they left off.
2. You wouldn't be able to get a username from a deleted account anyways, so it's pointless.

As FancyFoxy said, this wouldn't be a good idea for the reasons of finding your account GONE after being inactive for two years, and.. well.. if an account is deleted, then it wouldn't even free up the space for the username. For example, say I deleted my account.. you still wouldn't be able to create an account known as “LionHeart70”.
Also, what if someone decided to leave Scratch but still wanted to keep their account and projects since people like them?
useless fact, but a thread similar to this existed before

This doesn't help anyone but the people looking for usernames. I'm sorry, but on the internet, if a username is taken, it's taken. You won't get it.
Also Scratch isn't about usernames.

No Support

1. The user might want to come back.
2. You won't get usernames.
3. Even if you are able to because of this, doing something like this would confuse users into thinking you are the original user who uses the same name.
4. There are inactive accounts of important people on Scratch.

Guys I get it its a bad suggestion im sorry for suggesting something >:[

This is a terrible idea, what if @griffpatch had been inactive? We would lose all of his amazing projects! No support.