Simple Mobile apps have been very popular among FOSS enthusiasts. I've personally been using the Gallery, Contacts and the Phone app since a few years now. It's a shame that it has come to this, will be on the lookout for their forks.
Yes. If you have automatic updates enabled, it will install the newest version with trackers and ads. You could disable the automatic update for these apps and hope they stay relevant to your os for a little while.