Wouldn't e-bikes be a relatively stopgap measure? They still require a relatively advanced and carbon-wasteful technological base, after all: maintenance and repair for the bikes themselves (including regular replacement batteries, which are definitely NOT environmentally friendly), plus paved roads in good repair (again, requiring a lot of fossil fuel expenditure).
There's also the likelihood that as the Earth's environment becomes increasingly hazardous we'll require protection from the elements more and more often - protection which would be difficult to add to a bike of any sort.
The US military has projected that basic infrastructure in the USA will be collapsing throughout much of the country in less than twenty years. It's hard to see how ebikes will be practical under those conditions. Gearing towards long-term lower-tech solutions would seem to be a wiser choice.