I was by struck something that seemingly cannot be a coincidence, but of which no hints of a relationship or any sort of explanation is given in the Beyond the Mountains of Madness book itself. I can only assume that it is an easter egg-like wild goose chase (or seed for any Keepers who, God help them, want more side adventures), but I must admit it confounds me somewhat.

Specifically I'm talking about the Vredenburgh family, and their propensity to appear throughout the BtMoM storyline. Historically, the first one appears in 1838 in the Poe's The Narrative of Arthur Gordon Pym.

A sailor, Peter Vredenburgh of New York, is lost overboard on Jan 10th. Keeper’s note: the Grampus was owned by the firm of Lloyd and Vredenburgh, but no connection between the names is revealed.
— Page 179

And furthermore, the bark Grampus, is owned by Lloyd and (the second) Vredenburgh, although no connection between the two Vredenburghs are ever made in Pym's tale.

The third one appears some time after 1897, when Stanley Edgar Fuchs wants to sell the Pym manuscript, believing it to be fake.

The advertisement was seen by Nathaniel Vredenburgh, a wealthy ship owner in London. Vredenburgh wrote at once to Fuchs offering $500 for the work, but by the time the letter arrived Fuchs had already sold the signature to Percival Lexington.
— Page 326

And the fourth one of course, is Henry Vredenburgh, who comes to captain the Starkweather-Moore Expedition's ship, The Gabrielle, after the unfortunate death of Captain Douglas.

Three or four generations of Vredenburghs, spread out across almost a hundred years, all involved in some way with the Pym story and the Antarctic? Something's fishy.

I asked Chaz Engan, author of Beyond the Mountains of Madness about it, and he confirmed that indeed, there are purposefully plenty of Vredenburgh's, but that there is no actual connection between them; just straws for the investigators to grasp at.