I do not think it is weird if it's a genuine thank you. I always try to be very specific when I send thank you to teachers because I want them to know I'm not doing it because someone made me but because I am genuinely grateful. So I avoid stuff like "thank you for all that you do" and try to say things like "thank you for helping DS come out of his shell this year -- he always tells us how much you make him laugh and I can tell the humor and fun in the classroom has helped him feel welcome and comfortable." Like I try to think about what is special about that specific teacher and how they've helped my kid in specific ways, and call it out.

Elementary grades do not matter and can't be gamed, if anyone is thanking teachers in the hopes of getting better grades, that's dumb. Elementary grades exist for no other reason than to help identify kids who are struggling so that they can be given more or better supports.

Is it weird for me to email a thank you to a teacher when I haven’t talked to him at all? Because I volunteer in school I have seen him in passing but I hate interrupting to say hello and I also suffer from social anxiety. I fear I may have come off as snubbing him or being rude and then just sending a nice thank you now to affect end of year grades. Maybe I should wait until report cards are posted? But then he may not be checking his email over summer. He hasn’t given special attention to my child or anything, but he worked with child’s class of 20 all year and I know gave up some of his free time to support them.