It looks like Windows. If it behaves like it, then you can read the full title by hovering over the tab.

I haven't used gnome in quite a while, so I'm not totally certain of what was before this change, but I wouldn't consider it problematic. I find that saving the extra 20 pixels at the top is good for the widescreen aspect ratio of most monitors.

For what it's worth, you can see the entire title by hovering over the truncated text in the tab.

IMO, the title isn't really helpful anyway. I did a userChrome.css thing a while back to make it just show favicons in the tab bar with one or two pixels of space and it works great. The tabs don't jump around when you switch tabs and you can fit a bunch more of them in the same space (I keep favicon bookmarks on the right side of the tab bar).