I'm guessing you're going to get spam and phishing emails because of this. I don't think anything in that spreadsheet could be used to hack your mastodon accounts and whatever bot downloaded and runs through the spreadsheet isn't gonna know what a mastodon handle is and will probably just try to add it to their email lists
But! I have informed you!! I did my duty for sneepsnop and snoopsnort
next year i will look into alternate form builders