I doubt anyone can give a 100% answer. It may hold forever or it could take off. If you can catch it with your fingernail it's most likely too deep to polish out.
I have two scratches that deep in my 41gl rimless however that glass is 3/8" thick. My has held water for 10mos.
If it's in the budget you might consider removing it and replacing that pain. Also since you plan on painting, you could substitute smoked glass for that pain.