I don't think how hackers get any info just in that way. I think they can get our email because can see it on bounty spreadsheet.
I haven't come across any spreadsheet that displays it's hunters email,they always treat emails delicately which should be so, if there are such bounties, then it's crazy to be on them.
Emails are private and as such should be treated that way and thats what most bounty managers I've come across do