For the most part, yes but maybe closer to 20 years. These are newer UNIX machines and they can get software upgrades.
Swapping out the entire system for an entire infrastructure upgrade? Not happening.
The upgrade process for such environments is not new. You simply run a parallel system with the new h/w and s/w, the new parallel system receiving all the data of the old, and outputting data separately for comparison, testing, analysis, etc. You can then move segments of the new system into live operation, once convinced the operation of the new system at least meets the standards of the old.