No they don't. They can only speak for themselves. And getting to a round of 16 or quarterfinal stage next year in the CL, if that happens, doesn't negate the disastrous Europa league campaigns that have been taking place for Serie A squads for the past decade.
Serie A built up a very strong war chest in the mid-late 1990's and the early part of the 2000's with the successful CL and El campaigns.
They could "afford" to have a few down years without it greatly affecting their CL and EL places. The war chest is empty now. The playing fields throughout Europe are as even as they have been in a long time.
If the rest of the Italian clubs don't do something in these European Competitions, and soon, then Serie A is going to lose that 3rd CL spot, and this league will be no better than the SPL or Eredivisie by the end of this decade. And that is going to be a major, major problem for the future of the league.
For all the talk of La Liga eseentially being a 2 horse race, that is true. However, what is grossly overlooked are the successes of the other squads from La Liga who have, and are, putting together successful campaigns in the Europa League. This is one of the reasons why La Liga will never, ever lose their 4 CL spots. It is high time for the Italian government to allow other teams to build their own stadiums and to whatever it takes to increase revenue throughout the league, or us as juventus fans, are going to be extremely disappointed in the next 10 years when no champions are going to want to come to a league as bereft of quality as what Serie A will be in the future.