I don't think he's been "lead writer" for quite some time on the games? He also hasn't "produced" the games in a while, meaning he's not actually the person in charge of the game's production.... likely just the money man contributing because he likes it.
According to Lazlo, he wrote most of GTAV's main script (i think it was either in one of those O&A or Joe Rogan interviews) and a lot of RDR2, either way, his and his brother's authorial presence has always been there, because all R* games share a very strong DNA in common (for better or worse, maybe now that he's gone, they'll fix the slow ass controls).
TBH i doubt they'll keep to the 1 game every 10 years credo, which to me was partly due to their boneheaded obsession with world building details (since it's what they always ramble about in interviews), that made their games unique.
But yeah, of course we'll see how the next game will turn out.
I'd lie if i said i wasn't shocked by the news though, i would've never guessed a R* games without the Houser brothers (Dan in particular, since he was the main creative force of the two).
