4. Another Fallout Expansion
Despite Fallout 4's critical success and large sales numbers, many hardcore fans and casual gamers were disappointed in what they felt was a dumbing down of the RPG classic's mechanics, demonstrated by the addition of a voiced player character and the removal of the skill system.
Fans were left wanting more, and the lackluster amount of DLC released (only 2 major expansions) didn't help Bethesda's cause.
It is likely too early for the release of Fallout 5, but perhaps an expansion to Fallout 4, or a smaller stand alone title, is what Bethesda is planning to release in the coming months. An expansion could hold players over while they wait for the next major release. It could also provide bitter fans an opportunity to get back into the post apocalyptic series they know and love.
Fallout is a massively popular title and so is suitable for a quick announcement to release window. Gamers are aware of the series, so Bethesda could afford leaving out a long marketing cycle, choosing instead to release the expansion close to the announcement, generating mass publicity and anticipation.
However, Bethesda's dedication to its unpopular "Creation Club" could be a sign that it has different long term plans to hold players over until the next Fallout release.