That is largely hypothetical and one does not know if Elastic would taken a different form is Lucene would have been under LGPL, nothing in LGPL would have prevented it, and maybe Elastic would have chosen LGPL themselves or even AGPL which I personally would have preferred over SSPL but I understand why they choose SSPL and 100% reject OSI's position that is a non-open license, it is a non free software license, but it is IMO an Open Source license