Al Lowe did not pick up the rights of LS, Codemasters did in late 2008, after which they released the disastrous Box Office Bust. Replay Games was then allowed to use the rights to remake Leisure Suit Larry 1, following a Kickstarter 2012. Al Lowe and Josh Mandel were part of the Replay Games development team, but left the company (along with the bulk of the other employees and volunteers) when the game was released as the result of an internal dispute. Right now the rights are still in the hands of Codemasters and the future of Larry is unknown. Al Lowe went back into retirement and doesn’t own the rights.
And yes, Sierra is back, sort of. Activision revived the Sierra brand in August – it will serve as the brand name for indie games and to bring back some of the classic series. So far they’ve announced Geometry Wars 3 (to be released this month as the first title with the Sierra name) and a new King’s Quest (developed by the Odd Gentlemen and expected for release in 2015). While Ken and Roberta have no direct involvement in the development, they did visit the developers about a week ago to see what they were working on and, according to Ken, loved what they saw, so we’re very much looking forward to more information on this new King’s Quest game.
And yes, you SHOULD play Phantasmagoria :-).