I would expect that a player needs to play in a minimum number of games to qualify for a medal.
You may be right about that, although there would then be an anomaly, as I believe that Edwards (12 appearances), Vincent (12), Koszela (7) and Burton (0) all received medals, compared with Essuman (13), Nabi (11) and Banton (6), who may not have done.
I don't expect that the three players who have been out on loan for many months would believe that they would be entitled to a medal, but it does open up an interesting question. Perhaps either players who are playing for other clubs on the day of the trophy presentation do indeed miss out, or the League's trophy and medal suppliers feel that they should limit their expenditure accordingly. If there is a league rule or policy which covers this circumstance, I should be pleased to know what it is.
We do not know of course whether medals have been set aside for them. However, the hardest part of winning the championship or getting promotion is getting across the finishing line and players that have been put out on loan were obviously deemed not good enough to be part of the squad to be champions and therefore probably are less deserving of a medal denoting such.
The national league three trophies are only 3 years old - link
The first to present his case seems right, till another comes forward and questions him.