Complex sentence: What Egyptologists will make of it remains to be seen, but since the King and Queen are mentioned without a coregent, whatever coregency might be to come, it would be limited to a year or less.
Split into simpler sentences: What Egyptologists will make of it remains to be seen. Since the King and Queen are mentioned but not a coregent, whatever coregency was yet to come, it would be limited to a year or less.