Well the meeting on Tuesday is probably the most important since decisions were taken to end the NL and L2 seasons. I would be very surprised if the EFL did not emerge from the meeting with some form of agreed framework and that framework almost certainly will define the promotion/relegation protocols for all EFL divisions.
Whilst the meeting will be advertised to the world as one designed to achieve a total consensus however, in reality the EFL is unlikely to want to compromise very much on its draft framework proposal. It will fight very hard (if it has to) to stay close to the original draft and I'm sure that if necessary and unless the opposition is overwhelming it will at some point be prepared to play "hardball". So this raises the possibility that some parties may feel aggrieved enough to threaten a legal challenge (though this entire time-consuming process seems to have been designed to take the sting out of this potential threat).
As the EFL meeting constitutes an EGM, then any consensus will automatically create changes to EFL regulations which should then come into force immediately. The National League board will then be provided with the basis from the EFL either to convene a meeting or develop its own proposal for submission to its members prior to a meeting. The former could be done very quickly but would still leave lots of room for a free for all wrestling match at the meeting, the latter would enable the NL to remove things from the table that might otherwise be discussed (e.g. null and void) but would take more time to set up.
My guess is that they will see how definitive the EFL framework is. If it is a very firm affirmation of the existing relationship between the EFL and the NL it may well decide to issue its own proposal and if it did it might look very similar to the EFLs - the controversial element of which will probably shift to the issue of relegation from the NL. Clearly if the outcome of the EFL meeting on Tuesday is confusing or unclear then the NL might not have that option.
So we might not know anything for certain until w/c 15th June. Dont be under any illusion however that what comes out of Tuesdays meeting will significantly influence the answer to the question we all want to hear......Probably.