Large check given by employer marked as 1099-MISC?

Apologies in advance if there's any obvious information missing from this; I'm admittedly far out of my depth here and really appreciate any advice.

Recently, the small business I work for as a standard W-2 employee was sold off to a large corporation. As "a reward for years of hard work for the business," several employees and I were given large (over $10,000) checks in addition to our last paychecks from the business. Both are dated from December 2020. My concern is that these large additional checks are made out as personal checks and marked as being 1099-MISC.

Realistically, I just want to make sure this is above board and make sure I can file my 2020 taxes without getting hit with an audit. Is this kind of pay out after a company is sold something that would fit a 1099-MISC and I can file without issue, or do I need to try to get them void that personal check and put it through payroll?