In the work we've done, we see that by 2050 you'd need something pretty close to a zero-emissions electricity sector, which means that using natural gas, even efficiently in a combined-cycle power plant, is not compatible with that. You can decarbonize the gas stream. You could inject renewable natural gas or even hydrogen, and then there are modifications that would be required to make that turbine still operate with a high amount of hydrogen in it.
That being said, these units 30 years out may still be viable in terms of adding support to the system. They're there. They're standing by. You would use them very rarely, but they're still part of that system in terms of offering a diversified and reliable source of power should it be needed.