I can’t see any sign of RTS there.
However it is an 11 year old meter, so will almost certainly be out of certification and over due for replacement.
That will be why you keep getting the letters.
Meters are generally only certified for 10 years after which they need to be replaced - Ofgem rules say that a supplier should only supply electricity through a certified meter.
For more information on meter certification see:
New meters are all smart meters (they don’t make any other type anymore) so that is what you will get.
TBH there is nothing wrong with smart meters.
What you may hear about them ‘Not Working’ is misunderstanding, people are blaming the wrong thing.
The meters work fine, what can be a problem in some places is issues connecting with the network that they need to connect to to provide your readings remotely to the suppler.
If you do happen to have connection issues then you can still read the meter and send in readings, just like you do with your old meter.
If you think of it like a mobile phone, you wouldn’t say that your phone itself was faulty because there was no telephone mast nearby.
Or going back further you wouldn’t say a TV was faulty because you only had a weak signal at your house.