My former company had this culture. A team member who passed probation or got promoted would belanja the team to a lunch.

Nothing fancy la, for my case example I spent less than RM 300 to buy nasi arab and drinks for the team.

For me, such a culture was still acceptable because after probation you were eligible for additional RM 1000++ in allowances as a permanent staff. Also promotion to new position will come with minimum RM 1000 increment (and can be much more if you're promoted to higher position e.g. manager and above).

If the increment was like RM 100 I would also be offended if I had to belanja my colleagues RM 300.