Tauntauns must now disengage to leave melee, is it consodered a standard move and they get their dodge token?

Yes, they get a dodge token due to Agile 1. They can also use Reposition and Relentless. Ram will not trigger, however.

Ok, but under withdraw, it says „A withdraw is considered a move action.”, not that it is a standard move, like it is written under compulsory move?

"Standard move" is very broad.

From the rules reference (p. 53) "When a unit performs a move action, it performs a standard move, reverse, strafe, pivot, climb, clamber, embark, or disembark."

That's the lot. Leia moving you with a command card? Standard. Scout move? Standard. Withdraw? Standard. Vader shoving you with the Force? Standard. Anything that is a move and isn't a reverse, strafe, pivot, climb, clamber, embark, or disembark is a standard move.

8 minutes ago, rafparis said:

Ok, but under withdraw, it says „A withdraw is considered a move action.”, not that it is a standard move, like it is written under compulsory move?

To Withdraw, you perform a speed-1 move. Per the RRG entry for a Standard Move, "all speed-X moves are standard moves."

18 hours ago, arnoldrew said:

Ram will not trigger, however.

I just want to make sure I understand the interaction on this one. Will Ram not trigger because they can't go a full 3 speed move? Or assuming the taun-tauns can't reach another unit with a speed 1 move? Based on the language below for Ram, I wasn't sure if "maximum speed reduction" applies to Ram or just things like Immobilize.

A unit whose maximum speed has been reduced is still
considered to have performed a move at its maximum speed
as long as the move was performed using the highest speed
movement tool available to that unit.

2 hours ago, Weikel said:

Will Ram not trigger because they can't go a full 3 speed move?

That’s correct. The unit’s maximum speed has not been changed, it’s just been instructed to perform a speed-1 move.

It’s just like the interaction between Spur and Scout. Speed-x moves have no relation to your max speed, so increasing it with Spur does not mean you suddenly gain a faster Scout move.

There is an edge case though: if you have two immobilize tokens, then your max speed is 1 because each token reduces it. If you withdraw in that situation, then that speed-1 move matches your max speed and you can Ram.