The balls sound a lot tougher in the new design. From your wiki link:
> spherical fuel compacts each 6 centimetres (2.4 in) in diameter with particles of uranium-235 and thorium-232 fuel embedded in a graphite matrix
And from the article on Canada's reactor:
> The fuel inside of this vessel are solid kernels made from a mix of uranium, carbon, and oxygen, with each being roughly the size of a poppy seed. These kernels, which are covered in several ceramic coatings, are then encased in a diamond-like substance
Also, the wiki says "a fuel pebble became lodged in a fuel feed pipe to the reactor core." In the new design, there's "no on-site fuel storage, handling, or processing." If the fuel elements are just sitting there instead of getting moved around in pipes, there's little reason for them to break.
Agreed, they hopefully fixed that particular issue.
However, it is prudent to expect other problems in new technology. And nuclear reactors need a huge initial investment (they seem to be vastly over budget and time these days) and take a long time until they are available. It seems to be cheaper, safer and faster to go with renewables, doesn't it?
These are reactors small enough to build in factories. That's an entirely different situation from occasionally custom building huge reactors on site.
For now, we should certainly keep rolling out wind and solar as fast as we can. But whether they can run entire countries reliably through all seasons is unproven so far. They're backed up everywhere by hydro where available, otherwise fossil. It's entirely possible that mass-produced passively-safe nuclear will end up cheaper and faster than the vast amount of storage/transmission/etc we'd need for a 100% wind/solar grid.
See https://en.wikipedia.org/wiki/THTR-300 or if you can read german: https://de.wikipedia.org/wiki/Kernkraftwerk_THTR-300 with a lot of details.