Former insurance defense attorney here. This settlement only came almost 5 years after the accident, and 3 years of litigation. Yes COVID caused a backlog, but from my experience this is not a large settlement for an accidental death case (and BTW given the relatively low number, it may even be below the deductible, but maybe not if you add attorney's costs) . It's probably pretty easy to find a settlement for another accidental death involving the county (e.g. bus hitting a pedestrian) that is much higher (like above $1mm).
The fact that the trail in question is still open, with no apparent mitigation done to lower risk, tells me that the county doesn't see any increased risk here. If they did, they (or more likely their insurers) would have taken action. So I'm doubtful that there will be a crackdown, or any other increased anti-MTB efforts.
The sad irony is that if MTB was legal, and JORBA was involved in trails building/maintenance, it seems to me that there would be a better assessment of this trail, and whether it is in fact too risky, or mitigation measures can be added. I feel badly for the family of the rider (especially his brother).