Sending to preschool-am I being irresponsible?

My son got a spot at a half day montessori preschool that he has been on the wait list for before Covid. He would be going four hours a day, four days a week. This is a great opportunity for him but I feel like it might be an irresponsible decision taking him there during covid times when he doesn't HAVE to go. He is 3 and SO bored at home with me every day. He is not getting stimulated enough and is craving playing with other kiddos. Do you think it is too risky to send him unnecessarily when we are not yet vaccinated? We will lose his spot if he doesn't enroll now.