It appears there were at least 2 emails sent to promote the survey on AI tool usage.
One of them is titled:
2023 Dev Survey: Are you using AI tools in your workflow?
the other:
The 2023 Developer Survey is now open!
I understand these are promoting the same survey. Did you happen to check whether the prompt itself influenced responders? For example, when you invite people with phrasing like "Are you using AI tools", is it possible that people using AI tools are more interested in participating in your survey? Was that the intent?