Tossable Digits is an option. They state "As of July 2018, we have tested and you can use our Virtual Numbers to verify WhatsApp and Viber accounts using the "Call Me" method. The SMS option does work with a US Short Code as well. You may need to wait 60-120 seconds after you try to send an SMS verification code in order to have the Call Me option begin."
Not sure it still works, but it is an option. $3.49/month for the number with unlimited SMS and Voicemail, plus SMS Short Code support.
Damn, $15/month per line? At least Tarsnap is pay-as-you-go. Seems way too expensive. TossableDigits.com (1) starts at $3.49/month per number and pay per minute, with plans that drop in price as you ramp up. Pretty much the same service without the all-in pricing. And you get unlimited SMS, Voicemail and Call Recording. They've been in business since 2006 -- staying power. (2)
They also are offering Robocall Blocking -- a huge win. (3)
@seren6ipity: Yes, you can now have a phone number that protects your privacy.
@soundsop: Yes, it is a subscription, but you can cancel anytime, and it's still pretty cheap. One phone number + 200 minutes a month for $8. And when you are done with it, you can cancel the subscription, no commitment.
@inovica: We do have a pool of numbers, but it is large. And to prevent reuse of a number that gets a lot of unwanted calls, we disconnect numbers for up to 25 days to cause traffic to subside, and if it doesn't, we don't reuse it.