One issue might simply be for anyone who cant read English brilliantly.
They know the normal height signs and their trailer height, but if you’re in a foreign country or simply can’t read (uncorrected dislexia etc) and see a sign full of garbage, they might be tempted to just ignore it thinking its just saying something like “railway related roadworks”.
Shouldn’t of course and might not be the case here, but personally I’d put a temp sign up just stating the new bridge height like we have temp speed limit signs. Cheaper than having a bridge hit.