CEV have apparently planned new changes to the CL format as of 2018-2019. Source
No more Final 4, eventually neutral final match host, no more hosts (if part of the competition) qualifying directly to the final(s). Seeded teams, guarenteed spots for stronger federations, fewer teams gaining access through the preliminary qualifiers. According to CEV, "this ranking reflects the investments and performances of all teams representing the same country in Europe’s elite competition." This is the first time where I see privileges based on, I am quoting, investments. Because 18 teams are said to directly make it to the 4th round, aka. the group stage, leaving thus only two remaning spots available through qualifiers, I question directly CEV's logic here: "As for the previous rounds, the level of competition will be fairer, thus increasing the chances for teams from the lower-ranked National Federations to progress to the 4th Round." On the contrary, teams from not-"investing" countries and lower-positioned federations will have fewer chances to reach the group stage.
I liked the 2017-2018 format. The group stage of the tournament was mostly good, play-offs screened weaker teams but gave them European exposure and still allowed decent qualifiers to advance. Pity that this otherwise successful formula will now disappear after a life-span of 1 year.