The required action depends on the actual change and process. Have the issue assessed before assuming either that a new filing is necessary or that no further work is required.
Obtain an estimate tied to the reviewed response
Separate professional assessment, any relevant document preparation and current official charges. A commercial rebranding budget does not determine the immigration procedure or its cost. Ask for the estimate in two parts, because the first is knowable now and the second is not.
The first is the assessment: reviewing the corporate change, the employment record and the existing documents to determine what, if anything, is required. That has a defined scope and can be quoted. The second depends entirely on the assessment's outcome and ranges from nothing at all to a fresh petition with its own official charges, so a single number quoted before the assessment is either padded or will be revised.
Ask also who is expected to pay. A corporate restructuring is the employer's event, and the cost of responding to it is ordinarily an employer cost, but that is a matter of agreement rather than something to assume; households have been surprised by an invoice for work generated entirely by a decision they took no part in. Verify current official charges at the time of any filing rather than carrying a figure from an earlier matter.