Then apparently they will keep using reCAPTCHA.
From one of the issues in that link:
Already solved. See public/recover.html line 67
If recaptcha variables are not set, recaptcha element does not load; users can freely send password resets. Verified this claim by not setting variables and trying to do password reset locally.
@wangbus please double check my claims 👍
Which is expected since theymos already said he needs to use reCAPTCHA as his own solution could be easily bypassed.