In my opinion those people's opinions can simply be discounted. It's quite literally the game play loop for D&D.
1) The DM describes the environment(potentially trapped in the Feywild).
2) The players describe what they want to do(locate an archfey to get out).
3) The DM narrates the results of the adventurers' actions.
If folks consider that railroading, I'm not going to pay attention to their complaints.
There's no way for me to know, because it wasn't my game. There are far too many variable, including all prior game play from 1st(or whatever level they started at) to 13th level. For all I know they have two gods who owe them favors and made good friends with an archfey. That would skyrocket the chances of success for those two possibilities.
I can only accurately assess the chances for success or failure in the games that I run, because I have the information needed to do so.
Correct, there are a lot of variables. But you're still missing the point. This
IS the quest - to get out of the Feywild. It's not placing a DC on some jump over a pit, understanding a church signage, or following a few tracks. Those are all things DMs have to make up in order to keep the "play loop" going.
This is the primary objective. The one thing they have to do in order to continue their campaign. (Which they all want to do.) So, not knowing any of the chances for those things, because the DM didn't even think about them, or any of them, means the DM is making up odds with no real thought, just impulse.
That used to be railroading. The DM instantly narrowing or increasing chances based on how they feel. Is the pizza late and they're hungry? Did they have a bad day at work? Are they enjoying watching their players squirm and become exasperated? I think they call these DMs grognards, to note that they are old (or play old school) and are the gods of the world. And they will decide (with no forethought) as to whether the players have appeased the DM god.
All of your ideas with no forethought, just like blinking a group into the Feywild with no campaign tie-in whatsoever, can be considered railroading. And again, it can be fun.
I am ok with you and
@Reynard not accepting that definition. It's ok. Everyone on here has a different definition anyway. But once you drag your friends to GenCon for a once and a lifetime experience, and play D&D with a guy who says he used to play with Gary Gygax, and then he does exactly this, then you might change your mind.

Until then, I respect your opinion. It's valid.