I received pre approval for phuket sandbox on Fri 2 July and submitted requested docs at 9.30pm uk time. I just checked my status on the mfa webpage (approved) on Sun 4 July 8pm and printed my coe. My flight is on 16 July; with legitimate coe (and all the other necessary papers) could Phuket immigration possibly deny entry due to UK high risk status?

The could deny entry but I doubt it.

You need to check with embassy about it since the are the only ones that can help you with the problem.

OP, you may might keep an eye on the situation in reverse.

Labor Party for example urging borders with Thailand to be closed. 

Reported in Taiger and other news sources.

I'm in a similar situation as OP except my COE hasn't been approved yet. From what I can tell when ASQ went from 7 days back to 14 days the people who got their COE approved for 7 days quick enough were fine.

 

So hopefully you'll be fine for sandbox.

Any Immigration Officer has the right to deny entry into any country for reasons that can be mysterious sometimes, but as long as your paperwork is correct (Note :at the time of arrival)

you should be OK. Just keep abreast of the immediate situation until boarding 

Please let us know how you get on because there are plenty of people in the UK now either in the process or about to apply for the COE and have been sent into panic mode because of the Red List News,cheers KP.

Good luck.

11 hours ago, DrJack54 said:

OP, you may might keep an eye on the situation in reverse.

Labor Party for example urging borders with Thailand to be closed. 

Reported in Taiger and other news sources.

That report was about 4 weeks ago. Also it was not saying borders should be closed, just suggesting Thailand should be added to the UK Red list. Since then there has been a further UK review and Thailand stayed Amber.

7 minutes ago, jimn said:

That report was about 4 weeks ago. Also it was not saying borders should be closed, just suggesting Thailand should be added to the UK Red list. Since then there has been a further UK review and Thailand stayed Amber.

Anything possible in even near future.

Hospital beds reaching capacity. 6000k+ cases per day. Delta soon to #1 with a bullet.

Frankly folk are crazy to be coming for holiday. 

If coming back to live here different story.