No. I believe it's a cross between the variety grafted on and the pollinator.

I'll let someone else go into more detail

Eric

Eric is pretty much correct. The tree that grows from that seed will likely be a hybrid between the type of apricot tree that set the fruit and a pollinator. Rootstocks are primarily used to impart some desired quality to the mature tree, E.G.: vigor, or lack thereof; cold hardiness; heat resistance; dwarfing; disease resistance; soil preferences; etc. If you are looking into grafting scion material, look for a known rootstock that will perform well in your area, with the desired characteristics you are looking for.

AFAIK all appricots are self pollinators, so if it's a commercial apricot there is a 98% chance tha tit's a cross between same-variety. Having said that, the seed is likely to NOT present the same characteristics as the parent plants. The reason that effectively all apples & grapes are propagated from cuttings is that the same-variety seeds express different and usually inferior phenotypes compared to the parents.

After a few millenia of human selection there is no sense in throwing it all away using seeds.

Comparing apples and stonefruits is not necessarily valid. With self-fertile peaches/apricots and the like, there's a better than 75% likelihood that fruit from seed-grown plants will be all but indistinguishable from the fruit the seed was extracted from. If it's a 'landrace' type - like the 'Indian Blood' peaches - fruit quality of probably greater than 90% of seedlings is comparable to that of the original.
Not so for apples(grapes, I have no idea).
But, you'd have to grow that seedling through its extended juvenile period to reach fruiting age - and grafting/budding with wood from a bearing-age tree will cut that wait-time in less than half.
Your seedling apricot would, however make a fine standard rootstock to topwork to a known superior fruiting variety, but it won't be the same as the rootstock selection your grafted variety is on.