Has their speech therapist mentioned the tongue tie as an issue that needs to be resolved? Has your kid had any other issues related to the tongue tie? Be guided by that, not your dentist who is likely trying to drive up laser procedures.
My kid has a short frenulum, as well. When he was born, a nurse noted it and said it might affect his ability to nurse, and that if it did we should consider addressing it. No issues with nursing or anything else. Needed speech therapy, but it was unrelated to the short frenulum. He’s 18 now, never had an issue.
Read this and ask lots of questions of any provider suggesting this procedure:
https://www.nytimes.com/2023/12/18/health/tongue-tie-release-breastfeeding.html