root@tor1> show ethernet-switching table interface ae2
Ethernet switching table : 1 entries, 1 learned
Routing instance : default-switch
Vlan MAC MAC Logical Active
name address flags interface source
CUST-3 4c:96:14:1e:47:80 DR ae2.0
DR means "dynamic, coming from remote PE".
Once tor1 PE learns this MAC over ae2, it will advertise it.
There is nothing tor1 PE can do about this (or any other) particular MAC - until Your CE decides to load-balance a frame with this src MAC to the tor1-facing link. Or until You decide to configure it as static MAC.