With regards to Moultrie, Johnson, and Pinckney that is absolutely false. Both the federal enabling legislation in 1794 and the South Carolina legislation in 1805 were for conditional cessions to be granted on unilateral action of the state and under the state's terms. South Carolina's terms were to maintain a garrison there and keep the forts in working order or else the contract would be voided after a couple of years expired. Fort Johnson, for example was virtually abandoned by the feds within a year and fell into disrepair on their watch, thus voiding that contract within about 2 years of the cession.
With regards to Sumter, as I said - that's a far more contentious legal issue than the clear cut cases on the other three. On the one hand the feds did construct the thing, but on the other hand it was unilaterally ceded and, holding that South Carolina was no longer a member of the United States at the time, they were accordingly not restricted from repealing the previous act.