Let me just give you some advice from someone who also waited many years for a sequel to their beloved franchise (e.g. Unreal Tournament).
If a company doesn't make a new game after a few years from previous installment and are making billions of dollars in profit. It's time to move on, they don't care.
Can you imagine Nintendo not releasing a new Mario game every 3 months? It would be considered heresy.
Never say never though, we got Shenmue 3 released after 18 years. Even though it kinda was mid and sucked. Didn't sell well at all, so we'll likely never see a Shenmue 4-5 to series completion.
New import data shows around 70 tons of hardware declared as "Game Console" arriving at Valve between June 10 and 17. While the contents cannot be definitively verified, the shipments may actually contain the Steam Machine this time.