That may well be the case in all boarding schools (preps and seniors alike) in the land, Ridleyxf, but we are talking Eton here which have their unique ways of doing things. I understand, for example, at Winchester a boy is almost like being married to his housemaster right from the beginning when he has endless interviews over many days with him (like choosing a spouse) and throughout his entire career at WinColl, no doubt emerging at the end of the process five years later being heavily indoctrinated by the housemaster.
You don't find this nonsense at Eton. Interview at the application stage is a short half-an-hour or so process following a computer test. If offered a place, a house is quickly allocated like what the OP is undergoing now. Eton houses are huge, there are altogether 25 of them, with at least 50 or more boys at each house - 70 in the case of College - whose ages range from 13 to 18 with roughly the same number of boys in each 'block' (cohort). Each house is like a small school by itself with only the one housemaster at each house, including College. It is therefore, physically impossible to pay individual attention to each and every boy at a house. Most of the time boys at a house do things together as a whole group e.g. at meal times. Can you imagine e.g. the housemaster at College taking questions from 70 scholars at the same (often limited) time? Impossible!
Instead, each boy is assigned a personal tutor, usually a senior master or even another housemaster from elsewhere, with whom a boy meets twice or thrice a week in the evenings and/or weekends in a small group of between five and eight tutees at the tutor's private residence located anywhere in the campus of Eton. Both tutor and tutees oftentimes socialise together besides serious regular matters of academic and pastoral concerns, e.g. attending a show in London or simply a meal at Pizza Hut on a weekend, etc.
In fact, a personal tutor is such a significant figure in a boy's life at Eton so much so that a boy can request a new personal tutor in his final two years at Eton (Form 6) if he so desires. DS requested a change from a Maths expert tutor to a 'Medicine' expert tutor in his final two years because he was intent on going to medical school. The new personal tutor he requested happened to be the Master-in-charge of the school's Medical Society who gladly welcomed him as his new tutee. It was a very successful working relationship. BTW, DS's housemaster at College happened to be female (most fantastic and helpful woman in many respects) who holds a PhD in American History but had absolutely nothing in common with DS career wise. Like I said above, not a problem at all, DS had an absolutely fantastic 5 years at College with her at the helm.