Apologies if this gets asked a lot. When I google it, I only see threads that are a few years old and I think even say those methods are now outdated?

Is there any new or updated way to track Blizzard games through GOG Galaxy?

Thanks in advance.

On the left, click All Games under the GOG Store category. Enter Blizzard into the search bar on the right. Click one of the relevant games that turns up. Under Company on the right, click Blizzard Entertainment, Inc.. Click the Bookmark icon near the top left, to the right of the navigation arrows. Periodically load this bookmark to check for new releases.
You can do this with any kind of store search query, including a complex mix of tags and features, price range, etc.

If you want to know when a game goes on sale, click Wishlist It under the Add to Cart button on its details page.
Click your avatar near the top left and choose Account Management. On the right, click Subscriptions. Make sure the Wishlist Alerts category is enabled to receive e-mail notifications.
Click the cogwheel in the top left and choose Settings, then Notifications. Make sure the Wishlist category is set to either Desktop Only or Desktop & Overlay.

If you want to be notified when an upcoming game is released, click the Notify Me button on its details page, where the Add to Cart button usually is. You can manage the list under Account Management - Subscriptions as mentioned above.

If you want games to receive updates as they are released, keep them installed. On the website's library page, games with updates get a blue dot and there's an Updated filter to see them all. I don't think there's anything similar in GOG Galaxy though.

Other than that, I can't think of a way to track a particular developer or publisher.

It shouldn't be a problem, unless it's specific to certain titles, not "Blizzard games".