Well there is that but I was afraid that they may skip Echidas event which offer those units seeing as she and the time spirit are in the TP. But maybe I am just worrying about it too much as they will probably have her event after Arias so that you can get more MCs (moment Crystals) to get all the new units in the TP.
Or the devs could be very cruel and skip Echidnas event and let only those who are really luck with RNG to get the required bronze and silver units through summonings :P
Rotate the TP?!?!? My good sir what could you possibly be talking about. This concept you propose sounds foreign to me, is such a thing even possible.
But on a good note, we are having a good stream of events, do I dare fear the dreaded break on the horizon? I mean for old time sakes we have to have one right?...... *Prepares to have stones pelted at him for even suggesting such blaspheme*