It was merely one source, there are others.
The point is, it'd be distorting the truth if you said they were in favour of continued operation of the Pacers. But… there are, perhaps, bigger priorities than removing them without a credible replacement (which their members are happy with).
How many times have the RMT gone on strike over safety concerns regarding Pacers since 1985 citing safety concerns as the reason for the strike?
How many times have the RMT gone over strike over the potential removal of guards in 2019 citing safety concerns as the reason for the strike?
Noting there's conclusive evidence that Pacers are less safe than Sprinters, while there's no conclusive evidence that DOO is less safe than guard operated trains.