Yes, travel insurance matters for a trip to Anegada, and the honest reason is remoteness rather than any obvious hazard on this low-lying coral island. Unlike the volcanic peaks of Tortola or Virgin Gorda, Anegada sits flat and largely unpopulated behind Horseshoe Reef, one of the largest coral formations in the Caribbean, and getting off the island quickly in an emergency depends on a short flight or boat crossing rather than a road. Most visitors come for the reef, the flamingos, and the beach lobster shacks along Loblolly Bay, and a policy still earns its keep for lost luggage or a disrupted connection even on a routine visit.
Anegada itself has only a small clinic, and anything beyond minor treatment means a transfer to Peebles Hospital on Tortola, the BVI's real hospital hub, with serious cases typically evacuated further to Puerto Rico or, if needed, on to Miami. Confirm your policy explicitly covers inter-island medical transport and international evacuation rather than one that only reimburses a routine clinic visit, since the transfer between islands is the step most likely to involve real cost and delay.
Diving and boating are the main draws here, and both carry real risk this far from full medical facilities - Horseshoe Reef diving and the inter-island sailing common throughout the BVI are worth naming specifically in your policy rather than assuming a general water-sports clause covers them. Confirm any depth limits or crewing exclusions before booking a dive trip or a bareboat charter out of Anegada.
Hurricane season, roughly June through November, is a genuine consideration for any BVI itinerary, and storms can suspend inter-island flights and ferries with little warning, on top of disrupting the outer islands first. Keep any clinic paperwork from Anegada or Tortola, receipts for delayed travel, and evidence of flight or ferry cancellation, since many policies treat storm-related disruption as a standard delay claim but want documentation of the closure itself before paying out.