I think that people going into regions where they are likely to be exposed (such as people in the military) may still be given additional "boosters" for a variety of reasons including potentially mistaken records of previous vaccinations, variations in individual immune systems, and so forth. Easier to just give the additional vaccine.
True, and I can understand that thought, especially in a military setting but generally any American going to a place where diseases that are normally "one and done vaccinations" are endemic is recommended to "update" their vaccines.
I would just say, especially in the context of this thread on not having, shall we say, 100% confidence in Public Health officials and pharma companies, that when they say "Yeah this vaccine gives you 99% protection from this rare disease you are unlikely to ever encounter for life! Totally!" and follow that up with "Oh, you are going somewhere you might actually get exposed to the disease? You should get a booster, just in case." I question the lifetime protection claim.
FWIW MMR and Yellow Fever were both added to the DOD "Vaccines that need to get boosted/redone" in the mid 20teens. I had a heck of a time convincing the local Walgreens that I really did need an MMR at 35. I think it's mostly Measles they are worried about with that one. Interestingly, COVID is one the DOD isn't requiring us to update. Someone decided the disease wasn't bad enough anymore to be worth the publicity, lawsuits, and hit to retention.