I'm confused why you would think the artwork style would have any real influence of game updates. Textures and models are the extremely easy quick part of any game development, (hence why modders churn them out) the coding and AI interactions and physics are an entirely different thing that require the real work.
They have like one actual programmer. You can't just throw money at hiring others because its an artistic endeavor, not an assembly line. Not only do you have to make sure any candidates have the needed skills, but you have to make sure they mesh well with the existing team, can play well with others, and will be on the same page as to the direction of the games development and vision. That's a lengthy process, compounded by the fact that once a viable candidate is found, they likely have a current job they need to resign from which takes time, and then often pick up and move. And in the EU that often means moving to an entire different country, which is a bit more involved then just changing States in the USA. Then once that person is relocated and on board, well now you have to sit down and familiarize them with everything, all the quirks of the code, and that's going to take time as well. I'd imagine it'll take around 6 months from start to finish to go from starting the process of looking for new programmers to them actually contributing in a meaningful manner to speeding up game development. The start of 2022 is likely when we will really see the mass influx of money they had come to fruition with a much more rapid development speed.