I think it’s serious, GT85 is advertised as being a cleaner and remove dirt, while also lubricating due to PTFE content.

Now:

1. It looks like the current formulation doesn’t include PTFE
2. Which is good because it is one of the most harmful forever chemicals

I think it’s treated a bit like WD40 with its “magical” properties, they are both water displacing compounds that help clean away dirt.

As anyone would say: just wax your chain ;)

In my eyes it seems legit. As far as I understand, the quintessence is that you should not use degreaser when cleaning the drive train, as it removes fat from places where it should not be removed, e.g. in bearings and the joints of the chain, as it is impossible or hard to put new grease (not oil) back there.