Pretty sure it depends on the author. Some make it so the omega can’t move on, some don’t even have the bond thing in their work.
There's no specific rules in the omegaverse world, but the basic is that Alphas can have lots of mates during their life while the Omegas on the other hand are stuck with their Alpha that made a bond. (They would feel sick when doing it with others besides their mate). Only an Alpha can break the bond (like a contract).
From there authors will decide their own versions on what they see fit in their story line, either the Omega mate for life even after dead or move on with another pair.
Personally I would think it's cruel too to let the Widowed Omega stay single forever.
I have a question. If the alpha of a pair dies, what happens to the omega? Will the person still be unable to sleep with other people? Or do you think it will disappear?
Well i don't think it will just disapear but I find it really cruel if the omega is not allowed to find someone else to love. I am also always corncerned about the omegas that were forcfully bitten. I don't think that there is any way to break the bond but I am still hoping there would exist a way...