Dorival Júnior achieved some good successes with a few Brazilian teams in his manager career until now. However he has never managed a national team until this opportunity. This is what makes things really doubtful for now. The England - Brazil friendly match in 3 days is going to be his first experience with the team. What would you expect from this match?
My personal opinion is that this is a match that is pretty risky to bet on - on a side at least.
Because we don't know how Brazil players will play in the new manager's control.
As for Neymar topic, I agree. However he is injury-prone and he is injured right now too. This is why Dorival Júnior should make some changes in the way the team play. If you aren't strong in team effort then your chance to achieve something gets much lower.
I have good prospects for Dorival Jr as CBF coach for the next world cup, but if it depends on the current players, unfortunately no coach in the world will be able to perform miracles, as a team does not just depend on a coach, a team is a whole cog, and currently the lineups that are being made by the CBF are disappointing us brazilians, great players are left out while old ones are always called up, I won't cite examples of names because there are a lot of players and I don't remember. But I will cite an example:
brazil wasted many chances when they still had a chance of winning a World Cup, a great example of this was in the 2010 World Cup, when they didn't call up players like Ronaldinho Gaucho, Adriano, Ganso (who was playing at a high level at the time) and perhaps even Ronaldo (Fenomeno).
Dorival Jr had a great season at Santos F.C, winning several titles at the time when Neymar Jr was still playing there, so he has a very attractive CV worthy of a national team coach.
Since 2006-2010, the Brazilian team hasn't had a good team, it's been more than a decade... And I have no hope of a good team in the short term, maybe only in the next generation of players (in about 15-20 years).
brazil tried to follow the way of playing European football, based heavily on tactics on the field and left out all the art of football, dribbling, spectacular plays were in the background. It will take a few years for everything to adapt to the new way of playing, focused on tactical schemes, and it may not even work... only time will tell
The truth is: today European teams are far ahead of Brazil, both in ability and in the quality of executing tactics on the field.
Today, at the moment I say that unfortunately we don't have the slightest chance of winning a hexa if we continue at this pace in the lineup, even more so with Neymar temporarily sidelined, although he is often targeted for fouls and frequently getting injured in world cup matches.
And to top it off, in the last ~15 years we haven't had a good harvest, with few stars left like Neymar Jr, Vinicius Jr and Endrick (promising star, but hasn't reached the level of ace yet in my opinion).
A coach like Abel Ferreira, one of the best coaches in the world, would be ideal for the team, but I don't think even he would be able to significantly increase the team's level of performance with the current availability of players.