Could be; not enough detail visible to be 100% certain. What source is it?

the plant appears to be grafted and still plagiotropic, despite the size. Source is forestfarm.

No, it's not Abies borisii-regis.

It's a very poor plant.

Thanks Clement and Resin. Clement could you articulate why you think it is NOT borisii-regis? I am reading the guide to firs of the Arnold Arboretum. The stomata are indeed grey-green as expected from borisii-regis (they say alba should have white stomata). Is that that the buds do not appear to be very resinous? Or that the needles are shorter than they should?

Stomata colour isn't a reliable guide, variable white to grey-green in both. Ditto the amount of resin on the buds, variable. More significant is that at least some of the needles have notched tips like A. nordmanniana, whereas A. borisii-regis at least usually has acute tips. Looks more like A. nordmanniana in leaf arrangement, too. But having said that, I saw some wild A. borisii-regis in Bulgaria that had similar leaf arrangement – right next to another tree that had pectinate foliage very like A. alba . . . !

Can't tell from these pics if the shoots are pubescent or not; A. borisii-regis is.

Agree with Clément that it's a very poor specimen, I'd not have bought that. Do they have any provenance data for the thing?

Resin

I can ask for provenance - I wouldn't have bought if I could have seen it. Got it from mail.

First of all, very few non-cultivar Forestfarm conifer offerings are grafted, per at least a couple phone conversations I've had with them over the years concerning the matter. If they offer a straight species it was probably grown from seed. But you can always call and check.
Second, I'd withhold judgement on whether it's a very poor plant or not. Not great obviously, but I've seen worse. I'd want to at least see the state of the rootball before concluding that...I'd trade a bit of top unevenness for a too-bound root mass any day. The gallon-sized Abies recurvata and Abies pindrows I got from Forestfarm were quite "wonky" on top, the roots a little knotted but not too bad. I broke them up. Both plants are looking much healthier now, about as good I reckon as if I'd sown a seed in situ years ago. FWIW, Forestfarm is usually happy to send you a picture of a 1 gallon or larger plant if you want to see what it looks like.

And Abies are actually very resilient anyhow, if happy. (Which is a big if, I grant you.) I bought a couple 6' Abies firma years ago which had severely outgrown their 5 gallon or so field pots. (I forget the specific trade name but it's the system where a heavily perforated pot is buried for several years as part of the production and watered with mini-hoses) The roots were so knotted up in the pot I had to take a saw to them to break the circling, and cut the pot off by slicing it several ties with a box cutter. I ran the untangled roots out in a radial pattern even digging trenches for them. Well, those firs are doing great now, having grown almost 3' last year w/o any fertilization.

Due to poor sales of woody plants these days anything purchased may have been "stored" by the retail supplier for some time. You look for another retailer who may have the rare item in better condition - if you can find one - or you settle for what you were able to get. Many US nurseries have filed for bankruptcy or closed in recent years.

A search of the Oregon wholesale nursery industry online plant finding tool shows a grand total of nobody listing this species at this time.

http://nurseryguide.com/Find_Plants/Search?q=borisii-regis