Maxperson
Morkus from Orkus
"Often, players ask whether they can apply a skill proficiency to an ability check. If a player can provide a good justification for why a character's training and aptitude in a skill should apply to a check, go ahead and allow it, rewarding the player's creative thinking."There's also the text, under the Skills section:
The implication here really is there's a conversation going on between the DM and player. And a further implication is that the DM has said that a particular ability check is warranted - no specification if a particular skill has already been identified as being relevant - and frankly, I think that's not necessary to know. It wouldn't have to be an unskilled ability check for a player to come back with a suggestion of how their skill proficiencies might apply.
That doesn't say anything different than what I said in the post you quoted. If the DM does not provide a proficiency to an ability check, the player can suggest one.