People Are Split Over This Wedding Invitation

People are divided on whether this wedding invitation is SUPER rude or totally fine given the circumstances of the world right now. A photo of a wedding invitation has gone viral because people were categorized into 3 groups (group A, B & C). The invitation said:

Dear friends and family,
Please understand that our venue is limited in the number of guests we will be able to accommodate for our wedding day. As much as we would love to have each and every one of you join us on our big day, we are forced to split our guests into groups to ensure we do not surpass our capacity restrictions.
Group A: Please RSVP as soon as possible. We appreciate your promptness as we will be able to extend any vacant seats to any additional guests.
Groups B & C: Please keep a close watch on our wedding website for notice that we have space available. If you already know that you are unable to join us, it is helpful that you decline via the RSVP function on our website.
If possible, we encourage our guests to hire a babysitter for the night and leave your children at home. As much as we love your kids, we are doing our best to make space for all of the guests we can. We also ask our single guests to forgo their plus one if possible. We appreciate your understanding.

Tons of people are split on whether this is the right way to go about it or not. What do YOU think?! Super rude or totally fine?!