FFG has stated that not all career exist in the core set (best example is the rat catcher). They do plan to add to the career with additional products. The said Rat Catcher career will be in the adventure kit.
So you squire was not overlook and should be coming in a supplement
I know that FFG can't release every career right out of the box, the point was that I thought some of the initial choices of careers were a tad lacklustre. I mean the Dockhand career before the Squire? I know that there are some strange Careers in WFRP such as the Ratcatcher or the Bonepicker or Camp Follower and I have seen my fair share of these while playing WFRP over the years. I think I was just a little disappointed with some of the Career choices especially since I actually really like this version of Warhammer.
Keep in mind too that they have weighted it towards the beginning of the career scale (i.e. more basic careers than immediate or advanced). I would imagine including squire would suggest a second intermediate or advanced career should be included in order to make a reasonable 1 career advancement. As it stands now, it seems that all of the basic careers in a "chain of careers" has the next logical career as a progress. E.g. wizard apprentice, initiates, etc.