ESA/ UC reviews

Hi,
I am due an ESA review next month though as I will be within 6 months of retirement age am unsure I will get one. For many years the 2 year reviews were deferred for a further 2 years and it's been many years since I had a review. I am on ESA. A friend of mine who is on UC and has been for about 5 years or more had a text recently saying they were going to call him this Monday to " ensure he is on the correct level of benefits" etc. In other words, a review. He is about 6 months and three weeks from his retirement date.
If I do get a review and it comes in form of a text notifying of a phone call, but without an ESA 50, am I within my rights to request an ESA 50 to fill in and send them?
I have very detailed evidence from consultants occupational therapists physio's GP etc and if they refuse me an ESA 50 I intend to send copies of my evidence to both ESA handling site for care of a decision maker, and also for the attention of the case worker or office who are looking at any review. I am in North West so assume it's Maximus. Would they have to look at this evidence and take it into account? Just sending a text to inform of a phone call seems a sly way of ensuring there is as little evidence as possible to tkae into account

Not sure David I will ask him this weekend. He is pretty clueless to be honest I assisted him with his original UC claim he was never on ESA and also with his PIP claim. What exactly is a UC enhanced review and how does it differ from an ESA review? My original question still stands though. I have heard of people just being sent a text to say they will have an ESA phone review. If that were the case would they have to take any medical evidence and letters of explanation into account if I were to send them. I have GP supporting letters ready too if I do indeed get my planned review

He tells me it's from UC and names a jobcentre employee and it's "to review evidence already given, to ask for more evidence and to check he is on the correct payments/level of benefits". He wasn't able to provide photo evidence when he originally claimed and they identified him via bank and utility statements. They were asking him for bank statements a few months ago and wanted to check his ID again, as his passport hasn't been renewed since about 2003 as he's medically unfit to fly. He's never held a driver's license. So could possibly be something to do with that. But it's definitely not from a health care professional or anyone from Capita, Maximus etc. But I've never heard of this UC enhanced review team which David mentioned