That does seem a little concerning. You're right, it seems that there can be a debate on the case where you are a SaaS, for someone to say that the value of you

That does seem a little concerning. You're right, it seems that there can be a debate on the case where you are a SaaS, for someone to say that the value of your SaaS is all in its use of ElasticSearch, in which case you'd need to release all your code publicly and open source, so basically make your entire SaaS open source as well under SSPL. So it seems like a copyleft license in some way, where usage of Elastic could result in you having to publish your source under SSPL as well. But it's extreme in that it's not just your changes to the ElasticSearch source, but your entire stack. Honestly, I feel maybe ElasticSearch just doesn't want proprietary companies using it anymore. Either those need to use their ElasticSearch managed service or the Amazon one, or they need to themselves become an SSPL open source solution.