You should follow up very well once the mature palm has been transplanted.
The results of what happens when mature palms are transplanted and no effective follow up is done are quite numerous in Santo Domingo and Santiago. You will see plenty of dried palm trunks in public places, usually on medians and on triangle islands along major avenues. Most of those were planted as mature palms not too long ago and yep, they were planted by the government. The one's that actually survive are quite lucky.
If you ever wonder why when ever there is a median or an island on a major public road that is suppose to be lined with palm trees, yet they have so many gaps where its obvious a palm once stood; now you know. Not only do the mature palms dry up, but once they die they are not replaced with new mature palms (which given the lack of maintentance to ensure the trees survive, it makes sense to not replace them), so either the dead trunk remains until a storm knocks it down or the tree is already knocked down and the space where it once stood remains empty.
The next time a government road project is finished and includes transplanting mature palms, notice how many dry up in a matter of months, some even within a few days.
This is mostly a problem with mature palms transplanted by (or for) the government and on government/public property.