Counsel decides that, and the inputs are the completion date, how firm it is, and which entity would be named on the filing. A structure that changes while a case is pending can require further evidence or notification. A short wait is often cheaper than explaining a change midway through.
Put the corporate calendar on the case plan
Track the reorganisation's own milestones alongside the immigration ones: regulatory consents, shareholder approval, completion, registry updates. Registry records often lag completion by weeks, and an extract is only as current as the register behind it. Build that lag into the plan.
Where the employer wants a start date, express it as a number of weeks after completion and registry update, rather than a fixed calendar date agreed before either has happened. One further input belongs in that decision: what the requested period would be in each case. L-1A permits a maximum period of stay of seven years and L-1B five, and a filing made against a structure that then changes may need amending, which spends time without extending the maximum.
Where the completion date is firm and close, waiting usually costs less than explaining. Where it is soft and distant, waiting may cost a start date the business genuinely needs, and the trade-off should be put to whoever owns that date rather than settled inside the legal team.