When rhubarb goes to seed

No, just pull off the seed stalk low down as you don't want the plant putting its energy into seed production.

Rhubarb only goes to seed if it is getting dry or congested. The only reason you can't eat rhubarb is if it is getting very old and green and contains too much oxalic acid, usually much later in the season.
We've noticed in our relatively dry climate that some people trickle irrigate their rhubarb to get it to produce more stems.
If your clump is already very large, I'd divide it now or in the autumn to make smaller plants for next year, and make sure you replant it into holes enriched with masses of manure and compost.