Gideon shows up about 20 minutes late, because his sister's kids are a handful and also because the casserole and slutty brownies took longer to make than expected. As someone who exited the Order back when the going got tough, he's understandably nervous to be surrounded by all of his old Order friends, and the fact that Fabian doesn't put in an appearance is something that weighs on him as he settles down, flask of gin in easy reach.
Point #2 -- he wants to know how up to date the Order's intel on all known Death Eaters + their associates is.