I can't get over the fact that they first say:
"Amazon has a history of offering services that take advantage of the R&D efforts of others: for example, Amazon Elasticsearch Service, Amazon Managed Streaming for Apache Kafka,[...]"
And at the end of the article they promote how they themselves rely on other people hard work:
"TimescaleDB uses a dramatically different design principle: build on PostgreSQL. As noted previously, this allows TimescaleDB to inherit over 25 years of dedicated engineering effort that the entire PostgreSQL community has done to build a rock-solid database that supports millions of applications worldwide."
In the end, it sounds like they are doing exactly what Amazon is doing with open-source.
Also, in this case, Timescale actually has a pretty forgiving license[0] as long as you are not a add-nothing-aaS-provider, perhaps more than it should be, which I've asked about before[1]. Even before that change was made, running just the community edition as a add-nothing-aaS-provider would have been an improvement on the status quo, given how soundly it thrashed some other solutions in the past (ex. Influx[2]) and what you can do it (promscale[3]).
I know it can't be all roses, nothing is, but I don't think they've put too many feet wrong so far.
[EDIT] - I should note that on the scale of "contributing" to Postgres, the scale heavily tips in favor of 2ndQuadrant, EDB, and Citus as obviously they have the most committers and core team members. All those companies are to be commended of course, they're making postgres work as businesses and keeping it free while also improving it.
[0]: https://news.ycombinator.com/item?id=24579905
[1]: https://news.ycombinator.com/item?id=24585564
[2]: https://blog.timescale.com/blog/timescaledb-vs-influxdb-for-...