Nonsense, these people are talking nonsense!!!
Yes, older canes will rebloom. Several times in fact. As I mentioned, these are warm growing orchids how would they ever be exposed to a Cold Snap?? That makes no sense.
Reluctant orchids can often enticed into blooming by cooler temperatures at night for a period of two weeks perhaps. Take Phalaenopsis for example. Not a Dendrobium phalaenopsis but a regular Phalaenopsis. 95% of them flower without a problem. But once in a while one just refuses to flower. If you give it cooler nights say by opening a window in an enclosed room for two weeks, might make it flower. I suppose people try a refrigerator. If it grows year round at 68-75 degrees, maybe it won't flower. BUT if you give it 55-60 at night for 2 weeks, that might produce a bloom spike.
This change in cooler night temperatures is very important however in getting Drndrobium nobile and it's hybrids to flower. That's an entirely different subject.
