I don't know based on the rulebook.

The rulebook states on page 9 that when an Investigator places a Flashlight, "Placing the Small Flashlight makes spaces Bright and therefore Reveals any Hidden tokens on the mini-map. It also Reveals the Adversary, forcing them to place their figure on the main board." It also specifies that "If an Investigator is forced to move after placing a Flashlight, the Flashlight is removed from the board."

However, the rulebook does not describe any process by which an Investigator's forced movement after placing a Flashlight would cause other spaces to become Bright, nor does it explain if such movement would trigger additional Reveals. The only described effect is that the Flashlight is removed if the Investigator is forced to move, with no mention of new Bright spaces being created as a result of that movement.

To answer this question definitively, the rulebook would need to specify whether forced movement after placing a Flashlight can create new Bright spaces and if those spaces would immediately Reveal Hidden tokens or the Adversary.

Source: page 9.

Source: Core Rules (pp. 12, 19, 28, 8, 9)