You could tweet, email or WhatsApp GWR and ask them the question?This just now on their app about this evening’s 1736 departure from Paddington.
Correct. Cancelled any way now due to no set.Probably something to do with the spring tides

Apparently according to their app they're not serving the markow branch after 9pm tonight.
No reason given and no notification or alternative road transport.
Realtraintimes still have the trains listed as running.
Guess it will be a surprise if I get home tonight
Is there a particular reason Teignmouth is skipped? I can understand Dawlish as that's bearing the brunt of any rough seas/high tides, but Teignmouth is sheltered away from the shoreline.
Trains now reinstated.Showing cancelled on National Rail, shortage of traincrew.
So I’d use that over Realtime Trains. As always RTT won’t be exactly accurate until these trains are cancelled off in Trust.
If the engines get wet then there’s a not unreasonable chance that if the train stops it won’t get moving again; so best to make the next stop somewhere the train can be worked around (Newton Abbot) rather than where it can’t (Teignmouth).
April Fools are supposed to be before 1200 so I hope not.This just now on their app about this evening’s 1736 departure from Paddington.