You might want to be a bit more specific - some are, some aren't - I have two different versions of the G13B (the 1.3 litre used in the Swift), an 8V, SOHC which is non interference, and a 16V, DOHC which is.
I've not read about anyone eating valves (due to a broken timing belt) in any Suzuki or Tracker engine yet. I've read about people taking a good look at the 1.3L. 1.6L 8v and 1.6L 16v heads, and in their opinion, they believe them to be non-interfearance.
Well - let's change that ...
As I mentioned, I have two different Suzuki G13B engines, an 8v SOHC which is non interference, and a 16V DOHC which
IS - so now you've read about someone "eating valves (due to a broken timing belt) in a Suzuki engine".
I won't comment on the Trackers, and I won't comment on 1.3 & 1.6 16v SOHC - I will say
in my experience the 1.3 8v SOHC is
non-interference, and the 1.3 16v,
DOHC IS an interference engine - so at least one Suzuki engine is, and I would not be surprised to learn that more (especially the 16 valve, multiple camshaft engines) are.