UC Review Phone Call

Morning David, I just wanted to give a quick further update on the UC review call I had yesterday on behalf of my sister. As you suggested in your first response, I asked the reviewer what was the reason for carrying out the review. This was the response:
The DWP will contact the customer every 6 to 12 months to make sure that all the details pertaining to the customer are updated.
To keep an eye on customers expenditures and everything like that because the DWP is providing benefits.
To see if the customer is facing any challenges in their life, if they are not able to meet their life expenses with the benefits provided then the DWP will take the necessary action to support the customer.
Every 6 months the DWP will update the customers profile and if the profile is not updated then the DWP will take action to update the profile.

I was asked to provide 3 months of bank statements and a further call to discuss these statements has been scheduled for next week.
The things I find rather perplexing are that he kept referring to “updating the details” but yet he never asked for any further information of any details – so what details exactly are they looking to update?
The reviewer has not asked for any further medical evidence and did not declare this review as being an assessment for medical reasons (ie. we have already undergone a WCA in 2021 and my sister was placed in LCWRA) so it doesn’t appear to be a re-assessment for that.
He also refers to “updating the client profile” but gave no further information as to what exactly the existing client profile is and what needs updating (ie, what information is missing or needs updating).
Is this all just an excuse to monitor our bank accounts? We know that the government are passing a bill to have our bank accounts monitored but it seems as if the DWP have already started this themselves asking us to provide bank statements and then asking us questions about our expenditure? The reviewer also implied that this will be ongoing saying we will be contacted every 6-12 months. Are the DWP seriously going to asking us to attend review meetings every 6 months to go through our bank statements?
I appreciate you may not have any answers but just wanted to give you an update on the information I was told! Many thanks, Natasha