Seen on Reddit this morning, we have what appears to be an in-house announcement as to what we can expect to see from Dishonored 2. According to the document, Beta access to DOOM will be granted to those who preorder, much like with Wolfenstein: The New Order, giving people an extra incentive to open their wallets extra wide. Plus we will see a 'full reveal' of Dishonored 2 at E3 this year.
I know we shouldn't take these things at face value, but I am still hesitantly optimistic, as Dishonored was a very wonderful game and I want to see this series continue to thrive and be successful.
I have contacted Zenimax and Bethesda for a comment on this and will update if/when any news becomes available.
[Update:] Zenimax has responded to the situation with the following statement: First off, we would like to thank you for bringing this to our attention. We have not officially announced plans for the Dishonored series. If that changes we'll be sure to let everyone know. We are really sorry that we can't say more about it at this time. Thank you so much for being so understanding about it.