I'm not really trying to debate if coral can get Ich. It can't, fish get Ich.
I'm also not trying to debate if Ich can be transferred from a coral from an Ich infected tank. It can, in cyst form just like on anything from that tank.
I don't know if the coral frags I got from a frag swap or even my LFS came from an Ich free tank, but I dip all coral in bayer and QT in a fishless QT tank, but unlike fish, which I keep in QT for 6-7 weeks, I'm not sure if this is necessary with coral. After 2-3 weeks everything looks fine and bayer eradicates all pest in my experience. Wondering if bayer would have killed any Ich cyst?