Salam Alaykum brother
Ofcourse you can travel to Yemen but the Imam has advised us to wait for now till the day of the Bay3a
(Physical meeting with the Imam in Mecca to pledge Alliance face to face for he will call each of us by name as we are the first Ansar we pledged Alliance with him before meeting in Mecca)
The reason why Imam advised not to go to Yemen now is because he is not powerul enough to protect any of us, so he advised to wait till he can accomodate and protect us, and he predicted the Fitna in the Middle East will grow stronger and stronger and when it reaches it's peak the Ansar can escape to Yemen to meet the Imam or meet in Mecca when the day comes of the "Public Bay3a/aPledging Alliance"".
The best thing to do now is to read more of the Imam's Articles and spread this knowledge to people of the muslim and non muslim world. Please, be causious and careful in the beginning, you are allowed to keep your identity hidden and spread the imam's knowledge by internet or with trustworthy friends or family.
May Allah protect you brother
Fi Aman Allah