If I remember correctly, they've stated they don't have plans to ever migrate from Java to Bedrock. They've been doing a lot of work to try to get parity between the two versions but they're architecturally very different.

I'd be surprised if they hung Java out to dry - it's definitely seen as the "definitive" version of Minecraft among most of the dedicated playerbase. Although, Bedrock definitely seems like it's their big money maker with how many microtransactions are in it.