The licence changed in January from Apache 2.0 to a dual SSPL and Elastic License arrangement, which is a legal event with an infrastructure consequence.
# 7.10.2 — Apache 2.0
# 7.11+ — SSPL / Elastic License 2.0
$ curl -s localhost:9200 | jq -r '.version.number, .version.build_flavor'
7.10.2
default
# the practical question is not "is this allowed" —
# for almost every user it is — but "what happens at
# the next major version, and who decides"For an internal application the licence change permits everything you were already doing, and the real cost is that the upgrade path now involves a legal review rather than a version number. That is a recurring tax on something that used to be routine. The choice is to stay on 7.10, move to the fork, or accept the new terms, and all three are defensible — what is not defensible is discovering the question during an upgrade under time pressure.