Taking the SIM card out of an Android phone removes one route to the mobile network, but it does not turn the handset into an untrackable brick. GPS, Wi-Fi and the operating system are separate parts of the device.
Without an active SIM or eSIM, the phone may lose its normal cellular data connection and telephone number service. That can prevent a tracking app from uploading over the mobile network.
It does not physically disable the GPS/GNSS receiver, and it does not normally disable Wi-Fi. If the phone later connects to a known or open Wi-Fi network, services that were already configured may communicate again.
People often assume that a tracker follows the SIM because the phone has a telephone number. Most smartphone location systems do not work that way. The device determines or estimates its location using GPS/GNSS and other signals, while internet connectivity is used to share that information.
This is also why changing a SIM does not give a stranger a magic way to locate the handset. Knowing the old number or the new number is not equivalent to being authorized to read device location.
If the missing Android device is associated with your Google Account, check Find Hub. Supported offline-finding capabilities and recent-location information may still provide clues even when the normal mobile-data path is unavailable.
Look carefully at timestamps. A position from before the SIM was removed is still useful evidence, but it should not be described as the current position.
An already-configured LocationOf device may be able to record location while it has GPS but no internet connection and upload stored points when connectivity returns. Whether that happens depends on the app being allowed to run and the device later obtaining network access.
LocationOf cannot remotely install itself after the phone disappears and cannot use the removed SIM's number to find the handset.
Treat SIM removal as a reason to act quickly on account security and carrier blocking, not as a reason to give up. Follow the steps in My Android phone was stolen and preserve any locations you already have.
Changing the SIM does not replace the phone's Google Account, erase installed applications or disable the GNSS hardware. A new SIM may provide a different cellular data connection, and already-configured services may communicate again if the operating system still allows them to run. Whether that happens depends on the state of the device, account security, app permissions and network access.
The telephone number attached to the new SIM is not a secret GPS key either. The important point is that connectivity and location measurement are separate: GPS can determine a position without the original SIM, while a network connection is needed to send that position somewhere else.
Do not travel to an unfamiliar address to confront somebody based on a single map pin. Positioning has an error margin and the device may have moved after the last observation.
Not automatically. Removing the SIM can remove mobile-data connectivity, but an app that is already installed can remain on the phone. If the device later reaches Wi-Fi, or receives cellular data through another SIM, it may be able to communicate again if Android still allows the app to run and the account remains configured.
That is why a missing SIM should be treated as a connectivity change, not as proof that every recovery method has ended. Continue checking the official account-based recovery service and preserve the last reliable timestamps you have.