Switching jobs, stockholding association and insider trading

By March 31st I'll leave my current company for a new position elsewhere, and have a modest sum accumulated at the employee stockholding association (around 1.5M).

I've been warned against selling this until a year has passed (so at the earliest 2027/04/01) since this can be viewed as "insider trading". Does anyone have any experience regarding this?

I'm just a 会社員 with no access to non-publicly disclosed facts, although I work in procurement.

I asked the people in charge of the stockholding association and they just repeated the same about "being careful" about selling until at least a year has passed.

by NipponPanda