It wouldn’t be surprising. GTA Online makes so much money, Rockstar probably was in no rush to develop a follow-up game.
This is early build stuff, not worth judging it at this point.
Most games really don't exist as a playable format until about 1y before release, there are separate gates for features and content; content/UI/Graphics are worked on until about 2 months before release. Nothing before 6 months even looks like the final product in most cases: just a rough outline.
Like you had a very distinctive visual style on GTA 3, VC and San Andreas - which in part was probably due to hardware limitations, but R* owned it.
So it wouldn´t shock me if it would be something in these lines, to be distinctive yet familiar. Most likely the bigger improvements will be on online gameplay.
There is a huge expectation towards GTA since Rockstar has a history of being one of the best. The RDR2 was stunning on the previous gen.