Bay Blue,
Thanks for kind words, they are always appreciated.
The initial clues and evidence came from Unal Aysal (Galatasary Chairman) and Andrea Agnelli (President of Juventus), at a recent "Leader (In Football) conference in London.
It was said that
"Serious talks had already taken place and that all the clubs were in favour of it".
"It was to be set up to begin in 2018, when the current Memorandum of Understanding [ECA/FiFA/UeFA] expired."
"The top 15-20 clubs all agree with this."
"There may be one or two exceptions for local reasons, political reasons, but I understand this."
Agnelli added;
“If one was to break out of the system, probably the best competition that could follow is a closed competition with the 20 best European clubs,”
On top of those comments, a number of elite club officials have made similar statements and called for a super league in the past.
Bayern consider they have outgrown the German League, which seems to be a common theme among the powerful non English clubs.
The European based clubs also see the much richer Premier League and the income English clubs get domestically, compared to their own domestic leagues.
It is also worth noting that over the years, the threat of a European Super League has risen several times and on each occasion it has been stopped by UeFA caving in to demands in order to retain their governance and not lose their crown jewels.
I have skimmed that but it should explain what you were asking. Hope that helps.