I’m pretty sure that this was not meant to be the way it ultimately came across. As @hanssv suspects, there is likely to be a communication problem here.
I guess nobody outside of OTP knew this was being thought of, certainly not for 16 years, so nobody tried to be dismissive. You OTOH know, so it is totally understandable that it looks like that to you. But I don’t think it was intended.
(Adding to that, many older EEPs look totally abandoned, left to gather dust. Some are obsoleted by others even. Nobody knows if they are still considered or not. Maybe some cleaning up is in order?)
Regarding supplanting vs extending, well. I looked, and in the thread announcing EEP 70 here on the forum it was in fact worded as an extension to the language 
The way the overall process went here, especially in the case of EEP 70, was not at all ideal as well: The idea was proposed, the feedback was generally critical (or so it feels to me). Then it was decided to implement it, to the surprise of everybody who voiced concerns. Turns out there were good reasons for that, but they only surfaced later, in threads like this one.
Like, from the outside, it looked like bloating the language for little obvious benefit. On the inside, the decision to implement it was made for the benefits you guys saw in it, accepting language bloat as the price to pay for it.
So… where does this leave us?
First, lets bury the proverbial hatchet, shall we? 
Next… Well, I’m not saying that you guys from OTP should tell everybody everything all the time what goes on in your heads or team. In fact, I’m happy to think that you guys know pretty well what you’re doing 
OTOH, not being in the picture easily gives raise to misunderstandings and talking at cross purposes, like in this case 
So, please, explain, and early, don’t wait for the storm to break 
And on the other side… let’s give the guys from OTP some slack and put some trust in them
So, I hope we can get along better in the future 