Our focus has been on increasing the product for our existing members, but eventually we'll be improving the homepage/etc for people not yet familiar with the service.
Can you clarify on your point, though? PH has been around since at least 2013. The .chat TLD didn't go live until 2015, and that specific domain was registered is late 2017. Do you mean a specific features like todo or something?
Both sites are ostensibly primarily motivated by self-promotion, usually under the guise of some sort of public productivity tools.
BetaList (startup discovery platform) was created before Product Hunt, and WIP (our community for makers) is an offshoot of that. Product Hunt eventually launched a similar service.
FWIW, I have to strongly disagree that WIP is primarily motivated for self-promotion. It's really more like a virtual co-working spaces where we all share what we're working on (hence the name), exchange feedback, keep each other accountable, etc.
BetaList and Product Hunt are indeed partly about self-promotion and partly about discovery.