Hola Claire

There is not a clear nuance between the use of indicative or subjunctive here in this case with "lo de que..."; I can only think that if we choose the indicative over the subjunctive the speaker may want to present the information as a declaration, presenting it as new (even though it may not be) for it to have more emphasis/more importance. In the cases when we choose the subjunctive this information is seen as a background information, something everyone involved in the conversation knows. 

For example:

1. Lo de que tienes un trabajo nuevo me parece genial.

Here, although the listener obviously knows about this new job, the speaker is using the indicative to emphasise somehow that bit of information.

2. Lo de que tengas un trabajo nuevo me parece genial.

Here with the subjunctive, this information is seen as some background information - no specific reason to put any emphasis. 

Saludos

Inma