Not true. Check the Texas Waterfowl Digest. There is a season for them in Texas and I know of several hunters who have taken them here. Dont know of any outfitter guiding for them however.
He was talking about them being protected in Florida.
Though I don't hear much about Purple Gallinules in Texas, Common Gallinules or Moorhens seem to be fairly common here. There was one on our deer lease pond in Young County last summer.