Unfortunately the majority of UK sports fans couldn't pick Nielsen or Zeller out in a lineup - that's not being disrespectful to them, simply reflecting the fact that there are probably a handful of big names in British athletics who would have the name recognition to make this more of a story
I think it is a safe bet that there are going to be multiple appeals lodged by athletes who have been rejected and it is not impossible that it could also end up with litigation, although realistically, not sure if any of the athletes would have the financial resources needed to take the case to court.
If I was one of the athletes involved, I'd definitely consider taking the issue to UK Sport who ultimately bankroll UK Athletics. Given the board of UK Sport have board has at least 4 former Olympic/Paralympic athletes on the board, I'd be looking to put pressure on Katherine Grainger, Baroness Grey-Thompson, Chris Boardman and Annie Panter to comment on the fairness of the UK Athletics selection policy.
The best way to put pressure on UK Athletics would be to unionise - if they had DAS, Keely Hodgkinson, Jaz Sawyers, KJT, Laura Muir, Matt Hudson Smith, Zharnel Hughes and middle distance guys all coming out and collectively saying they didn't have confidence in the management of UK athletics and their selection policy, then it might grab people's attention and could potentially force a change but if the outrage is limited to the athletes mentioned in the article, then nothing is going to change any time soon. .