There is an enhancement request, ENH-000136517 - Requesting an ability to add support for GL Transmission Format (gITF) as input within the import 3D files tool in ArcGIS Pro. The status is "not in the current product plan."
The GL Transmission Format is one of five formats that the 3D Object Feature class can work with as described here.
Further gITF markers have some support in ArcGIS Pro as listed here.
