No, and I'll tell you why. One, the access standard should have built into it the kind of flexibility to address that. If the access standard for an automatic teller machine says you need equipment that will accomplish the following outcomes—A, B and C—then if they're testing something new, either it should meet those requirements or an existing ATM that already meets those requirements should be sitting there, and we, the user, have the choice to try one or the other.
You don't tell people with disabilities, “Well, we're trying out new steps, so until we finish trying out the new steps, no ramp.” It just doesn't make any sense.
Yes, there should be room for experimentation and innovation, but not at the price of accessibility in the interim. As long as there is accessibility in the interim, go experiment with anything new. Moreover, if you design the standards well, your question won't need to be asked, because the outcomes are what the standard might require: a machine that will enable me to do A, B and C without seeing or hearing or reading text.