Yes, you can now solo Legion raids, and Blizzard has even updated the Legacy Loot system so that Legion raids use it.
Legacy loot is coming to Legion content on March 31, but transmog and loot will still need a total revamp for Shadowlands
First up, I've always been of the opinion that the Legacy loot system for older raids is too restrictive.
Battle for Azeroth brought us many transmog and legacy loot changes, one of which was the ability to get full loot from all the LFR raids from previous expansions.
If you've been farming old transmog, like many of us do, but were frustrated by Dragon Soul still being on the original LFR loot system, then worry no more.
One of the changes in Battle for Azeroth that I love with an unquenchable passion is the upcoming Legacy loot mode, which makes transmog farming so much less painful.