28 Years Later Age Rating

Today I went to see “A Real Pain” which is rated 15 in the uk, if your from the uk you’ll know the whole “the following trailers are rated for the film” basically meaning you won’t see trailers for films that are above the age rating, I was pretty shocked to see the 28 Years Later trailer playing, I was under the impression it would be a 18 like the other two, do we think it’s going to be a 15 or is it just the cinema playing that trailer since it’s not all that graphic?