Still not really seeing it as marketing - especially since I've only ever been shown stuff for packs I already own?! The videos I think might be for all packs, not really sure as I haven't paid any attention since that update brought them. Since I've been playing Sims 4, the play button has been on the left side, and now the right - never the middle.
Not sure, as I haven't opened it for a while, but I think showing the packs you own is classic sims. Pretty sure Sims 2 had it, and even Sims 1. Can't tell you about Sims 3 as I never played it. Might have been on the launcher though, but I remember seeing it.