Slovenian proposal is a surprise, but who's behind it?

This is what Slobodan Zecevic from the Institute for European Studies thinks about the new Slovenian proposal, which surprised many.
Just a few days ago, Reuters reported that the remaining Balkan countries can no longer count on the promised membership in the EU, because Brussels can no longer provide such guarantees, the Financial Times published a completely counter-story at the center of the Slovenian initiative.
Slovenia, which currently holds the presidency of the European Union, presented a proposal at a meeting of ambassadors in Brussels on October 1, according to which the EU should expand to the entire Western Balkans by the end of the decade. This, of course, came as a surprise to members ahead of an EU-Western Balkans summit on October 6th, at which a declaration on enlargement should be adopted.
President of the European Commission, Ursula von der Leyen, who visited Western Balkans these days, reiterating her support for the countries to join the Union, practically hinted that this exact phrase should be expected in the declaration and nothing more. Politicians in the region have also been skeptical about this topic for a long time, because many EU members do not show a desire for enlargement.

Where did such a Slovenian proposal come from just a few days before the summit?

Zecevic reminds that Slovenia has previously stated the thesis that all the countries of the Western Balkans should join the EU together, but also notes that he himself, like many, is skeptical about that idea for many reasons.
The countries of the Western Balkans are not at the same level of integration. He reminds that there's a huge gap between Serbia and Bosnia-Herzegovina, between Serbia and North Macedonia and Albania, noting that Bosnia...