Interesting from Rumors and News thread....
There's a number of things that have to be done periodically to true steam engines like those on the WDW RR,
@4077.
Main thing is the boiler tubes have to x-rayed and any problems (cracks) fixed. Wheels that have ridden only in one direction (hits one side more than other) need to built up and turned on a lathe. Firebox (WDW loco's burn oil rather than coal/wood) may be burned out somewhat and needs to be replaced. Plus any other number of things to check.
Our Federal Government (your tax dollars at work) mandates periodic (years/# of hours in operation) rehab to look for problems, fix them, and put the loco back in operation before it becomes a problem.
Obviously this policy came into effect when some tourist railroads didn't check the boiler pipes, the firebox, the wheels, and more. Things went "BOOM" unexpectantly.
Strasburg RR (in Pennsylvania) is equipped to handle that (as is my "home" railroad in Chattanooga which is the Tennessee Valley Railroad
https://www.tvrail.com/restorations/ ) who maintains their own 3 steam locos from A-Z including complete rebuilds).
The main issue in these periodic checks is how much manpower to assign to the project. Put some manhours on in full-time to push through or make use of man-power when "slack time" (somewhat predictable) is available to work on other projects not belonging to Strasburg RR.
Disney has multiple loco's still available to operate so they could take the low/slow bid from Strasburg to get this done. Strasburg RR was in the news not long ago when they had a little bumpity-bump a few years ago which obviously required a fix.
https://www.trains.com/trn/news-reviews/news-wire/strasburg-collision-damages-no-475-no-one-hurt/
Do you want the work done cheap and later or do you want the work done right and soon?
Disney made their call.
Ed
PS - I've ridden Strasburg RR twice over the years (most recently 2021 IIRC) and they have a long record of operation . But sometimes, no matter how good of an operation you have, the odds catch up with you once in a while.
PPS - there's only a handful of places that can do this steam loco review/rehab from A to Z and Disney may not be one of them. Oh, it knows how to operate them on a daily basis but the extensive back-shop operations that are required for a rehab, it may not have.