Most members who were TAs back in times were considered mature, still caused problems. Also the burnout rate in TA is nowhere close as in any other staff group, even GK/GM/ES - the job isn't fun, beginner tourneys suck ass an so on.
Still not my call whether to bring back TA or not, so these are just my thoughts. Of course it wouldn't hurt to try, but it requires having some top staff member interested in taking over the group - otherwise it'll turn to shit pretty fast.