Since we're on the topic of the rebel meeting: it just ends. There's no sort of May the Force be with you moment where the gravity of the situation is conveyed, except a little on Mothma's comments as Venal pointed out.

This should be a "we have to win this or all is lost" moment. "It is desperate for us. We got our butts kicked in ESB and now the imperials are chasing us all over the galaxy. This is a huge gamble. Fail and we're finished."

It just doesn't have that gravity.

In the existing film, the rebel fleet just masses near Sullust. Maybe instead the rebels are forced to go there and combine forces because the empire has all but cornered them there? They realise the situation has grown dire and time is short for their side so they have to strike now before the DS2 is completed and the empire dominates forever.

That would up the tension a little. The rebels have to attack now. They've been cornered.

edit

You know what is also missing? Why the empire are such evil basterds. Their ruthlessness. I would love to see some of that come across in this film but I dont know how. Maybe the empire starts completely clearing the forests of Endor for settlement? I don't know.