I’m pretty sure the beta just looks bad because they slapped the new HD models on just the old maps with the tileset just shaded/smoothed to look updated. Compare this to the 2018 Culling demo, which had an entire new map, with updated tiles/trees to fit the visuals and look of the new models. This is even more telling by the comparison of even the minimap pictures. The mini map of the demo is new and graphically apealing, the current beta one is the exact minimaps from classic. This was quite foolish on Blizzard’s part as there can’t be real visual testing when the map terrain isn’t really updated to fit the new look.
Hopefully, if there’s an update today, they’ll use new/different maps to show the game looks better than it appears along with the visual fixes.