Twitter API had traditionally been configurable between read-only, read-write, read-write + DM. Most apps request either of the latter two, but you always could.
There's no write-only API keys, all keys come with read permission. If you didn't encounter discussion of any of "Key", "Secret", "Token", "CK/CS" while configuring that, and are thinking of apt/yum/brew installable terminal packages and IFTTT and likes, that package or the IFTTT backend are the apps and the maintainers will have to do something about it.
My bots are set up through dev. I wasn't saying my bots don't have read/write access. Just saying that my bots _only_ actually write, and I was hoping I could perhaps still use them for that purpose without having to pay.
Yeah, I'm seeing mass announcements of shutting down. I think some are holding out small hope that something will change in the next few days. I just checked and I have six active bots.