The "we can only uprate once a year" statement is a lie. Otherwise you wouldn't be getting a £10 Christmas bonus every year, bearing in mind that was a temporary payment set in the mid-70s and has to be agreed every year. It's not automatic, no matter how derisory.
The trouble with newspapers like the Mail (I'm being generous) is that they have staff who know nothing about the benefits system and tend to believe that there is no one on any other type of benefit. After all, UC was supposed to have been fully rolled out years ago. They haven't a clue about "legacy benefits."
The government's own website has details of the statement:
https://www.gov.uk/government/news/mill ... -of-living
I've picked out the most important bit - the emphasis is mine, because it's easily missed: "The significant intervention includes a new, one-off £650 payment to more than 8 million low-income households on Universal Credit, Tax Credits, Pension Credit
and legacy benefits, with separate one-off payments of £300 to pensioner households and £150 to individuals receiving disability benefits – groups who are most vulnerable to rising prices."