I just received one of these invitations from Westover, and I can second (third?) that they do seem very similar to the mass emails we received earlier in the process.
And the last class date is March 5th so it won’t really be an option to revisit these options after M10. That leads me to think that they have separate events lined up for accepted students? Either way, I’ll be waiting until I’ve received decisions to register for any boarding school related events.