Don't make it an easily searchable name, as far as i know private streams don't show up on a search (I use the term "private" loosely since site mods can see even those)
Adding stuff to "don't make an easily searchable name", I wouldn't attempt this. a 20-character stream that is named "klgslfixoekdjfkdkciw" would certainly violate spam policies. I'd rather see someone discover it by guessing it.
Sooo, basically you want to leech imgflip's bandwidth so you can have your own private online gallery to hotlink memes or photos from without having to re-upload them every time you want to post them.
So whats the point of it? You have "Public to anyone who has the link" which is basically private, and one where nobody can join it and only you can post is useless.
If you want them posted but not visible to other people, you could just download them. If you want the memes to be public but not the stream then thats a feature that should be made.
Now you resort to petty insults. Why? Because your point has no basis in reality or sound reason. Also, who would care if you had followers in your notifications. If you just start a stream for your images, nobody is gonna follow it because no one will ever find it anyway. I have started 2 streams and one had a single follower, me, and the other only has 19, and it has been around for almost 2 years. This makes zero sense