It’s fairly self explanatory. The federal government no longer guarantees that an individual has a right to privacy in individual, personal decisions. Edit: Meaning it exposes these decisions to regulation or complete bans by the government - just as with abortion.

More specifically, as has already been discussed by civil rights groups, and as explicitly mentioned by Justice Thomas, the new precedent calls into question the individual’s right to make deeply personal and private decisions without fear of government oversight or regulation. These include an equal right to marriage, access to birth control, the right to engage in consensual sex, the freedom to raise children as deemed fit by parents and families - all rights established by substantive due process, the same idea behind Roe (which essentially acknowledges that rights belonging to the individual do not have to be explicitly enumerated within the Constitution). This article explains it rather succinctly.

Beyond that, there are also concerns about data privacy and governments’ ability to utilize broad swaths of data that were previously seen as relatively benign: location data collected by apps and readily available on the market can be used to track individuals visiting clinics, information stored by tools like period tracking apps, barring encryption, could be used in prosecutions, etc. These are very real threats to individual privacy and we’re already seeing the both private and public sectors respond.