This wasn't how Jordan intended to end AMOL. He always intended to have some sort of post LB epilogue section, some of his notes for it are many years old. Among his specific notes for AMOL, he made for himself a grocery list of various character and plot points he intended to resolve in the book and of those he wanted to specifically leave unresolved (the list also includes worldbuilding issues to resolve or leave unresolved through the book - we know of one from that list: RJ intended the question of the "reality" of LTT in Rand's head to remain open, though his notes have the final answer, that was for himself as a writing guide, not for his readers) . Brandon pointed out Jordan's wishes will be respected, neither the books, the Q&A or the Encyclopedia will give answers to issues Jordan specificied should remain open) Much of the material on that list is concerned with post-LB and/or "last scene" developments (we just won't know before reading it if that "last scene" is the ending of the LB or something set later). As long as we don't read the book we won't fully understand, but what we know for now is that Jordan planned an epilogue after the "last scene". The last scene proper he had written in full early (several thousand words), the epilogue section is not in prose, but Sanderson has Jordan's own "grocery list" of elements not to forget to include/exclude, and Jordan's story notes/character files to go to to get the details. Sanderson already said he doesn't have to invent anything as Jordan had developped in his files pretty much how he wanted each issue, character, plot points to get resolved (not necessarily at the very end of the book, I would guess - it's more like the planned exit from the series for everyone, whenever it happens). He just warned there are some issues/plot points where Jordan's notes still featured options, and Brandon had to make a final choice in those cases. Where Brandon has had to invent the most is that for quite a few minor players, all Jordan left as notes for what happens to them since their last appearance in the series and until the end is their "series's exit" status, their role in AMOL itself was still TBD as he developped the book. Brandon had to decide how to best use them in the book to build to their "exit" planned by Jordan.