I think people have to try and remain calm and not buy into Marvel's trolling of the fanbase in regards to Secret Wars. Marvel LOVES working the fans into a froth by making them fear the worst, (in this case, letting fans think it's a total reboot) when it's really probably not going to result in a whole lot, at least in regards to the characters and their histories. We may end up with a new world after Secret Wars (though I would imagine not Battleworld, but possibly a reconstructed but maybe somewhat altered Earth) and some refugee characters from other universes, but there have been lots of signs from many books, including Loki, that everything is remaining intact in regards to continuity. Loki is not being wiped out only to be replaced with Ultimate Loki (isn't he dead, anyway?) Marvel has put so much work into the character recently they are pretty unlikely to just kill him off now, rendering this whole series kinda pointless. And the new Thor book just got started rolling, and Angela and both of them will be mid story when Secret Wars hits, just like Loki's book, but can you really see them ending those books/characters? With Thor smack in the middle of the whole 'unworthy' thing, and Angela without an alternate universe counterpart to replace her with? if they don't replace them, why replace Loki, when what we have now is the most popular incarnation outside of the movies? (and they are not going to use MCU versions of the characters, since that would completely screw up the MCU) so... yeah. Be calm. He's not going anywhere. Even if the book is cancelled, it is likely it will be relaunched, and even if it isn't Jason Aaron
said he has plans for Loki in Thor's book, so he will still be around no matter what.