That's very courteous, 28 days is plenty of time to find a new tech job. A real courtesy would be a golden parachute worth at least 6 months wages if you get laid off without cause. That's probably not more than a US sign-on bonus.

The alternative is giving real contracts to international hires, who already have a proven track record (otherwise why would you hire internationally).

Trial contracts were meant for people straight out of college, but in a race to the bottom some companies have started pushing that line further and further, even having people move across the world for temp contracts. You can't complain about labor shortage while behaving like that.