Worried

my wife has several complex disabilities cardiomyopathy , opsteoporosis, neuropathy, Parkinson’s disease and also depression and anorexia nervosa, she has been on DLA highest rate for care and mobility for many years and was given a lifetime award . She has just received a letter stating that her DLA is due to stop 13th may and she has to apply for PIP, she has carers that come in twice daily as I am retired, it used to be three times until I retired. I have already got letters from the hospice, hospital consultant, key worker and Gp supporting her claim, however my wife’s anorexia which had been stable, has now got where she has stopped eating since we got the letter, as unfortunately this is how anxiety affects this condition, also she has social anxiety and being seen face to face for an assessment is something that she absolutely will not cope with, and her Gp has included this in his letter, in the past she has not had to be seen and recently her ESA was up for renewal and she was not called in for an assessment for that. I am just wondering , does everyone get called in for assesssments? Being honest the letters that we have from all give all the information that they should require, the man on the phone from the DWP, whom I just spoke to regarding assessment, told me everybody has to have an assessment, but I am sure I have read on other forums, of people who have been awarded pip and not had an assessment 
thanks Steve