I'm not sure I understand comments about, or the need for releasing a matching set of 3 steelbooks in the future for any ongoing series.
If it's really, really, really important to you to get matching steelbooks in a series then why would you want 3 more releases of John Wick steelbooks when there is a 4th movie coming? If you want matching steelbooks then wait 25 years to life for the series to end. But the only way you can be sure that a series is over is if the actor playing the only main character dies. Even then you can't be sure.
There will probably be a John Wick 5. Studios just won't release a matching steelbook for a new release movie to match previous movies. It's not in their best interest. It makes more sense for them to continue to release something different because they know some people will buy it and then buy 4 more steelbooks when they release a matching set of 4 and then the cycle will continue.
Yes there are rare exceptions such as the Fast and Furious series. They continue to release matching steelbooks for that.
Remember, studios do what they feel is in their best interests, not yours.
All the "we pay a premium price for these steelbooks so they should make them match and not be lazy"(so tired of that word) comments
are ridiculous. 40 bucks in the studios eyes is not a premium price. You will never pay a price for anything in your life that the head of a studio would consider a "premium" price unless you're buying his house or his studio.