I wouldn't trust Dell with this. I have a Dell monitor that I bought because it has a USB-C port that supported both PD and video. But it turns out it doesn't work well with MacBooks (constantly loses connection, and messes with the MacBook's sleep). Dell acknowledged the issue and released a patch that fixed it ... for Windows machines. They refuse to fix it for MacBooks because they don't want to support a competitor's product. So I would be highly skeptical of a Thunderbolt dock from Dell working well with MacBooks.

Addendum: That monitor is also a dud in many other ways, notably that the PIP and PBP feature sucks and it has horrific ghosting. All a real shame as Dell used to have high standards for their monitors.