If it's still the same shite they proposed last time, it would ruin it it for any team not already in the top bracket in their league. When us and Villa finished fourth, we would have been out in their equivalent of the Conference League IIRC, because the top two leagues are there to protect the ones already at the top.
Once in the top tier of this 'unified league' , only the bottom one or two drops out, and only if they don't finish high enough in their domestic league or something stupid like that.
So for us, we would have had to have finished top 4, then finished at worst runners up two seasons in a row to get to the 'CL' Utterly ridiculous system that will never work.