Yes. From the original announcement: “HTML + JavaScript-based front end, powered by your system’s native browser engine (like WebKit, Chromium, etc.)”

From the email-walled “whitepaper” [0]: “If you need tools like the Base database module (including Java-based components) or the full Math module, Collabora Office Classic remains the right choice - Collabora Office isn’t trying to replicate those. Collabora Office will run macros, but for advanced macro authoring and debugging you should use Classic. For extreme Calc workloads (think complex Solver models or analysis across hundreds of thousands of rows) Classic is likely the better fit.”

[0] https://paste.c-net.org/FuriousWhistler