I am not very sure of what is the benefit of the change. To me, both situations are fine, so I am not deciding my vote yet :)
I was not a member of the site when its scope was set and I assumed such questions would be always off topic because, in general, questions about lists are disallowed (Why are "shopping list" questions bad?). It would be nice to read the reasoning from the initial members, since I could not find it in this Meta.
We decided to feature our Resources for learning Spanish but I am not very sure how much it is used to prevent such questions. For that, it would probably help to have it added in the How to ask section when you ask a question, but this is something beyond this discussion. However, it is indeed used as a source to answer (I use it as a bookmark myself, since I can jump to CORDE, CREA and so on with one click).
The bad part of moving this question to the main site will be that the featured post won't be there anymore. Also, this will free a spot in the off-topic closing reasons.
The good part is that we will be able to use it as a target to mark as duplicates. Will this be useful? I am not very sure, since such duplicates won't be very useful and will probably be deleted in the long run.
Which is, in fact, what Charlie expressed few weeks ago:
Así abrimos la posibilidad de preguntar por otro tipo de recursos más específicos, como "¿qué diccionarios hay que se especialicen en términos científicos?". ¿Qué haríamos con estas preguntas? ¿Marcarlas como duplicadas y añadir una nueva sección en la pregunta canónica? ¿O permitir que se desarrollen por su cuenta?
Lo único malo que le veo a esto es que ya no podríamos marcarla como featured y dejaría de aparecer en el cuadro a la derecha, donde creo que tiene buena visibilidad.
If we do this change, we also have to check what answers are we exactly moving, since it currently covers so different aspects, some of them way beyond "learning" and more into the "experts" field.
I have done some research over the main language sites in Stack Exchange and found an interesting discrepancy: all of them have such question, only that some have it in the main site and some in their Meta.
They have those in the main site, as a decision after Are resources for learning French on-topic?. I find it specially relevant since the debate was proposed by Gilles, a user with a big knowledge of the stacks and, hence, his solid reasons are always a must-read (which in this case I happen to support).
They also have:
About learning French: means and methods to use.
Ressources pour apprendre ou améliorer son français.
In Meta I found the discussion Learning resources for beginners they led to the wiki question Resources to verify French words, expressions, usage, grammar in the main site (funny thing they also mention us as using this in Meta to disallow resource requests).
This was discussed in Are questions about learning resources allowed? and they insist in that they are disallowed, only that they created such question in the main site in a Community Wiki mode, so that it can be used as a target to duplicate against. This lead to Resources for learning German
I found the debate Are questions asking for resources on-topic? quite interesting, since it shows a broad set of visions and reasonings on them, with references to other stacks and how they work on these.
I don't see an accepted answer, but they seem to have chosed to have those in Meta: Resources for learning English (migrated from the main site).
As indicated in one answer in ELL, Japanese has a Meta question Resources for learning Japanese.