Just a quick update for September. Still no substantial change in the situation. All US photographic retailers I've been checking online about weekly, which normally stock Velvia 50 in 120 format, remain out-of-stock (B&H, Adorama, Unique, Freestyle, Samys, MPEx, Amazon.com). Since I first started this thread, among those retailers, only B&H has occasionally had stock, I'd say for about a week or so, every couple of months. None of the others have. Velvia 50 in 120 format has basically dropped off the face of the earth, in US stores.
Meanwhile I see it pretty consistently in stock at various European retailers (Fotoimpex, AG Photographic in the UK) and Japanese retailers have been consistently in stock this whole time (Bic, Yodobashi, Amazon.co.jp).
So, this US (or North American) shortage continues, going on for a straight 6 months or more now at least (some of those US retailers I've mentioned told me they haven't had any since late 2020). Do we still think this is just a normal supply chain problem and nothing to be concerned about?