They'll likely get hot and/or woody, Cindy.
Not sure that letting it go to seed would be of benefit if it's a hybrid, but you could certainly try it. I let a good landrace variety set seeds and for the past several years I haven't even seeded radishes ...I just thin out whatever sprouts. I find it very difficult to grow radishes here any other way. Our climate is just so very indecisive and contrary!
