I'm wondering how these recommendations work. Does an author just call up an editor and say hey yo i like this series, then the editor put an recommendation ad on it?

. Murata also did the same thing for Act Age but on his Twitter lol.
I’d imagine either
A: the SJ editors hit up old popular authors and say
“hey, there’s this series we think you’d like that we think has a lot of potential. Here’s a few volumes, tell us what you think”.
The author reads it, gives their opinion. And if they like it, the editors will quote the author on the next volume release.
B: I’m pretty sure most old artist keep up with Jump to an extent even when they’re not in the magazine. I mean, most of them were probably huge fans of the magazine growing up before they were published. So a lot of them are probably aware of what series is running.
I’m sure the authors themselves don’t go out of their way to shoutout a new series often. But I’d imagine the editors may hit some of them up every now and then and say “hey, is there anything new you’re enjoying right now?”