My husband and I are going on the Tour of Southern France in May and wondering if we need to apply for an ETIA?
No, not yet. Maybe the end of year but who knows. Follow ETIAS on this website
https://travel-europe.europa.eu/etias
No. ETIAS will not be in effect in May.
Your airline will nag you incessantly to complete this as soon as it is required. This sort of thing will not be a surprise.
if and when it ever arrives it will be ETIAS, each letter means something. That is not plural of an ETIA. The "S" is part of the name.
Nothing to do now or for many months.
Since 2019, there have been repeated announcements about the ETIAS launch happening "in the coming months." The latest schedule pushes the launch to the end of 2026.
Considering the current mess with the EES implementation alone, I wouldn't worry too much.