Could be. You'll have a better idea by this time next year.

In the meantime, prune away any "normal" material from around the cluster so it gets some sun and doesn't get itself lost.

fingers crossed.
~Dave

Great - definitely keep an eye on it. That's how we've found several new introductions - from mutations growing on nursery stock.

Sam, I hope for you that this is a broom.
But I don't think it is one...
I've seen this several times before here at my nursery, the smaller buds on it's lower side are probably the cause of a bud damage from spring or summer last year, which is the brown part on the underside.
Because of this damage, it made several new buds instead, which you can compare to candle pruning.

Another thing is that a witches' broom starts always at one point, this is not the case here.

Again, I hope that I'm wrong, and you found a nice broom on this 'Meyer's Dwarf'.
Please, keep us informed on this one!