MBA sponsorship has a lot of nuances indeed.
If after graduation you want to change offices, 1st of all the destination office needs to accept you (& your debt), which is not so straight forward.
Then, the conditions are 99% of the times different, since you move to the financing conditions of the new office, which applies to your sponsorship in a retroactive manner. For instance, from Spain to US, you would loose part of the sponsorship amount -on the other hand, salaries are much higher in the US-.
Hope it helps!