Vindicated by History/Real Life

Automobiles

 * The Daewoo Nubira was criticised at the time of launch (June 1997), but and by 2003 at launch it got a slightly better reception. Its replacement, the Lacetti/Nubira, in 2002, got a better reception but was still seen as inferior to the Opel Astra. Now its replacement, the Chevrolet Cruze (or the Daewoo Lacetti Premiere in Asia and Oceania) has been criticised for being somewhat anodyne, the vehicle appears to have been Vindicated by History to a degree. So much so it's become an unlikely Cool Car.
 * In Australia, the Ford Escort (the MkII version was the only one sold there) was never popular due to sales of large cars like the Holden Commodore and Toyota Camry, but now with the downsizing trend, it's again been vindicated by history. It's become a Cult Classic again (but on a mainstream scale).
 * The Renault Safrane, a luxurious hatchback with "edgy" styling. However, it's the originals (that is the Mk I, 1993-1996, and MkII, 1996-2000) which have now been seen as great, if underrated cars with excellent engineering. The latest Safrane, from 2008, is unrelated to this, and a rebadged Renault Samsung SM5 / Renault Laguna.
 * The Vauxhall Astra MkI sold well in its time, and got good reviews, but was seen as being rather anodyne (in looks terms, anyway, given its razor-edge looks). It was similar to, but did not have the same design as the the Opel Kadett D (Mk4) with slightly different styling. It's odd that two similar vehicles with similar styling got radically different opinions by the then-contemporary motoring press. Needless to say, the car is a Long Runner in name terms, 31 years for the Astra name in Europe.

Other

 * Black Lives Matter. Mocked initially by some, but grew in prominence until by 2020 most Americans support it at least tacitly.