Wildlife charity Plantlife has been campaigning for some time and has seen significant improvement in the verge management by some councils. They've even published a management guide to help all those involved in management the highways. The pandemic may also have played a part last year by causing delays to mowing regimes.
The basic improvement in management is about giving wildflowers the chance to set seed, by mowing less and much later in the year, with one cut as late as possible, around August or September, and another before Christmas or by the end of March.
Ideally the cut grass should also be collected to take excess nutrients off and open up the soil surface for seeds to germinate, but many councils cite the expense of the machinery as a disadvantage. This is because as the soil becomes progressively more depleted nutritionally, the number of species in grassland will increase as dominant fast-growing species such as tall grasses and nettles lose their advantage.
As far as Herefordshire goes, the council states on its website that "a small number of verge locations, where it is safe to do so, are not being cut this year as part of a biodiversity trial. Verge cutting is carried out to both enhance the appearance of an area and assist with forward visibility for road users."
Read this Guardian article published last spring for some of the history of council roadside verge management changes.