The tokumx flavour of mongoDB that RSA uses in SA 10.6.x has reached its EOPS by the third party percona: Percona TokuMX: High Performance MongoDB Distribution . This is using backend mongoDB version 2.4.1
MongoDB have also stopped supporting 2.4 since 2016. Support Policy | MongoDB
However, RSA Security Analytics 10.6.x will not reach its EOPS until October 2019 and RSA has agreements with its customers to Support them at least until then. Product Version Life Cycle
What is the official response on this from RSA?