Should I Merge My Two Brands?

I have and audience of +76k on Twitter which I built over the past 2 years (call it Brand-1). I am about to launch a new marketplace app targeting the same audience but under a new name (since the twitter name is a not suitable name for a marketplace). Let's call the new app (Brand-2).

Here are my options:
1- Keep Brand-1 as a separate project from Brand-2 since it already has many followers and an established brand compared to Brand-2 but use it to market for the Brand-2.
2- Merge Brand-1 with Brand-2 and make it the community section of Brand-2. This will strengthen Brand-2 and keep the users in one platform. The downside is that Brand-1 will be discontinued as a brand and this could cause some confusion?

Your feedback would be very appreciated