There is no reason to think that more reputable activist providers like Mullvad or AirVPN would if a party like PIA already doesn't.
I'd steer clear of NordVPN though. They have lots of controversy in their history and they are very financially motivated, considering the deluge of YouTube sponsorship and ads they pay for each year. Still don't think they would lie about no logs but why risk it.
Did they also testify under oath there is no lawful intercept API or anything similar? That does not require logs. In fact when the feds would set up phone call intercepts on telco switches we would intentionally disable logs and put the mainframes into "test mode". And that is even before people start playing legal word games like calling lawful intercept "debugging" or something else. Lavabit [1] found out what happens if lawful intercept is not available.
Just me personally, I would always assume a service I do not entirely control and operate is doing what it can to comply with lawful intercept requirements and they are likely playing word games to not drive away their members and I would not blame them. I am just the properly paranoid type in part due to a good upbringing by a properly paranoid person.
I say you've properly got your eyes open. Anyone who thinks anything you do online is completely private is naive. IF any government wants to know what you've been up to online, nothing can stop them. Privacy is a thing of the past, we should vote only for politicians who say they want the government out of our backyards, banks and bedroom. Oops, too late!
However, I also think threat model comes into play here. If you don't want advertisers to track you or to download some torrents, a VPN provider works great. If you want to hack into NORAD, probably do that from a secondhand laptop on Tor over a public wifi.