Painless gum bubble/bump, is tooth extraction necessary?

Painless bubble on the gum, really close to an infected tooth

I had a painful tooth infection that required RCT but my dentist told me to fix the other tooth before doing this one so i can eat on one side of the mouth, last month I got really busy and forgot about the tooth because there was no pain whatsoever (the nerve probably just died)

A couple of hours ago i felt a weird bump on my gum near the same untreated tooth, it is completely painless. I went to the mirror and saw that it really is a bump, it's not that big, and is painless.

What are the actual chances that RCT would save the tooth? I don't want to extract the tooth. Is it savable yet?