Board Thread:Theories and Speculation/@comment-31512236-20170815153944/@comment-25122992-20170815172729

Again, TSBs aren't a necessary trait of SPSM, just a possible addition. Plus, Naruto lost 6 of 9 TSBs even before the final fight agains Sasuke and didn't regenerate them back, using only 3 left in this battle. It means that TSBS cannot be regenerated, and it's very likely that Naruto lost the remaning 3 in the explosion of Indra's Arrow against his Ultra-Rasenshuriken.