@Richard ********
Foreign governments are always overly cautious. That being said, in this case, they're legitimate. However, you need to do your own research.
Foreign governments will say things like "we recommend you reconsider your need to visit border areas of Myanmar at this time ". The reality is, if that border area is Karen/Kayin state, you won't be allowed to go there if you wanted to. Thai authorities will prevent you from leaving, while the Burmese authorities will immediately apprehend a white person found in the area as we're not permitted to enter Karen state due to fighting.