Pictured here is the ones by Velorian for E-Bikes
Bicycle indicators are available to purchase and there's some variety going from gadget that breaks in a day to proper ones. But there is surprisingly little of them and most of them run on batteries and standard bluetooth connections which I think is kind of ass for something safety critical.
Anyways germany, in 2024, finally made bicycle indicators legal for all types of bicycles instead of only 2 tracked ones or where the way it's built would make it impossible to use your hands and people have gotten cracking at building something, to me, better.
This one hooks up to the E-bike battery, which at least in germany will keep on the lights even if empty on reserve power because LEDs don't take much. They also build one with a dedicated battery pack and wired everything you can hook up to your dynamo to recharge as you ride which imo takes a lot of hassle out of it.
Everything is of course made to esoteric german safety specs and as such the pre-order model costs about 200 - 250€ all said and done. But I'm guessing in a decade these will have arrived at a more reasonable price.
Not as of yet, as all kits for this are retroactive furnishing and since I don't think the bicycle equivalent to the BMW or tesla guy is much of a tinkerer, generally, they probably won't shell out the like 200€ a shop would take to install this.
Having said that, as it's now legal here I'd expect to see it be slowly introduced first for premium cost e-bikes as a standard and then maybe filter down, so in due time: probably