The Steam Program is partly all PR and if no locomotives are running for 4-5 years then the PR concept is thrown out the window. They need to have at least one locomotive in operation while the Big Boy is being restored. The miles they run those locomotives, they really should have more than 1-2 in operation.
Yes, it's interesting how the D&S and C&T can keep 4-6 locomotives in operation under daily use, working to their limits but the UP program can't restore another locomotive and keep 1-2 other locos running in the process.
I understand that it is not a passenger operation and it's just PR ploy and they do not have to do it, but showing that they want to restore a Big Boy and the fact that they just put BIG money into moving it and making over the shop shows me they want to keep the program.