It's all well and good if all the measures are applied but social distancing and alcohol do not go together. If there's two things that make Brits lose their heads it's sun and alcohol. At least with sun if people are outdoors the virus is less virulent.
There'll be plenty of pubs that just let people do what they want and there'll be no shortage of people who will just do what they want anyway. And it's not like going to Primark where you're in for 10 minutes and then leave. People spend hours in pubs and even if they sit in the same place they still need to use the loo several times more often than not.
Opening them on Saturday under a big publicity drive just exacerbates the issue, rather than a low key midweek opening. It'll be chaos over the weekend. I certainly won't be going to a pub on Saturday.