Orbán hasn't done that because of Serbia

"Viktator", as some media call him, a bad politician who angers Europe with his attitudes towards LGBT and migrants, paid for an ad in the Croatian Vecernji list entitled "On the future of the European Union". In it, he listed seven proposals that would improve the EU, and the last one concerns, no less and no more, Serbia.
"Serbia should be granted accession to the European Union," it was written in Orbn's announcement.
Croatian Ministry of Foreign Affairs reacted immediately, with a clear message that it does not share the views from this advertisement.
"As for the EU enlargement process, Croatia insists on enlargement based on consistent fulfillment of membership criteria, implementation of necessary reforms and achieving measurable results. This applies to all candidate countries for membership, including Serbia," Croatian MFA says, as Blic reports.
This announcement caught everyone's eye because it is a kind of precedent, so far it has not been noticed that any EU prime minister publishes the announcement, especially in another EU country. In addition, the question arises, where is Serbia in all this? And, more importantly, what interest does Orbn have that Belgrade deserved so much attention from him?
Serbia has good relations with Hungary, which is reflected in the fact that the President of Serbia, Aleksandar Vui, and Viktor Orbn met as many as eight times from May to August last year. Orbn can appeal to the EU to accept Serbia whenever he can, but the question is how much it helps, having in mind his status in Brussels.
Orbn made an unusual move after the EU summit, at a dinner that, according to the media, lasted until two in the morning, and at which there was even talk of expelling Hungary from the EU and publicly...