Unless I have missed it, we have yet to hear what might have happened yesterday, which presumably is still being investigated.
Just because it was an 800 yesterday, doesn't mean that an 802 might have problems on another day, does it?
No one has ever declared an 802, or an 800 come to that, to be 'Dawlish-proof' - like I said, the technical specification for that the IEP required the design to take account of the need to avoid issues like those known to affect Voyagers. In the light of what happened yesterday, they may need to revisit that aspect of the design. But perhaps let GWR and Hitachi find out what actually happened first.