Yup, that's eggs.
Snails breed when they are happy, and when they are stressed. In my case they get all romantic in the spring cause I open the windows for fresh air. My heaters aren't very strong, and it's a big change from being in a room that's steady heated to 68 degrees.
They won't likely survive, but it's good food for the rest of your tank. Just double check that your params, especially salinity and temp, are on point. Probs just the stress of transfer to your tank.