That's what I did a couple weeks ago when I upgraded from a Droid Turbo to the Pixel XL...bought a 4-pack of Anker USB-C adapters and just attached them to my various microUSB cords. Power charging and data connectivity have worked perfectly, no issues.
As previously noted, that should work fine. I have used the Samsung charges, and block charger, using adapters, and they have worked also. May not charge as fast, but they work.
I did some more research on this issue, and found a great source of info. Not surprisingly (or -- maybe surprisingly) -- chargers are not chargers, and cables are not cables.
The link below is to a site that provides an incredible resource of information regarding chargers, and in particular USB C chargers, and the conformance (or non-conformance) to the USB C spec, and the potential for many of the non-OEM chargers to cause damage to phones. This made a believer out of me, and steered me toward the Google chargers, despite the cost. There is also analysis of related cables.
I think it should be fine. The only thing i would be conceded about is if you purchased a random no name brand charger for $4 lol. I'm just weary of using those things. Just make sure the USB-C adapter is from a legitimate source and you should be good to go!
At the end of the day, a charge is a charger. Just make sure the output from the charger isn't too high for the phone to accept.