Yes, all the gas usages can and will be replaced by electricity. Which will come from renewables. The 3 remaining German nuclear reactors won't make much of a difference here, but yes, those which are in any shape for it, should run e bit longer. Though one has to take into account, that the maintenance was set up according to operate them to the end of the year, so a lot of maintenance would be necessary for any longer operation time.

No where there is abundant nuclear visible, new build projects have vastly overrun any time and fiscal budgets.