Its a wise precaution by Leeds, sometimes you have to make the right call even though it might hurt.
Wider implications may vary - without knowing exactly who the player is and which other teams he or she has come into contact with in the last 2 weeks
then it is difficult to know what the repercussions of this will be.
Best case scenario is it is a player who hasn't played the last two weeks and it is only the Leeds squad who is effected.
Worst case he has played against 2 other teams, it has then got out of control - but could also have got out of control in the first scenario, this is the way with these virus's
For me the league should take proactive steps to understand the spread at this time
Check each squad player for the virus and any squad that is effected should be stood down from games for the next 2 rounds
Immediately suspend all games at anything other than first team level
Those two steps will allow the max number of games to go ahead.
They should repeat the testing on a weekly basis to confirm still clear or now clear
It couldn't be too much of an issue as each club has medical staff and testing 30 players each it could be done in a day