Intel 4 is already in high volume, Intel 3 is Intel 4 with process tweaks and extra libraries so that should be doable. They will both run in the same fabs.
Intel 20A has been pulled in from 2025 to 2024 and I’d imagine Intel 18A is Intel 20A with process tweaks so not going to need new fabs or anything like that.
It’s a good tactic for Intel - stuff TSMC foundries with Intel wafers so other companies have to use intels foundries