Interesting, are we just talking UK?I don’t think you’d be able to operate Blackpool tower, most of Warwick castle, discovery centres, shrek and possibly London eye, dungeons and some sealife centers.
Some of Merlin’s international sites have opened up and for example Australia has got everything open again (Sealife, Madame Tussaud’s, LDC, Tower Eye etc)
Obviously the other sites will be watching what happens to those that are open but unless some government rules stop them here I can’t see anything will stay shut unless it’s extremely hard to implement changes