A lot of smartphone makers these days are starting to drop the headphone jack from their phones. Even OnePlus who had previously held out on removing the hardware feature is doing so for the upcoming OnePlus 6T, leaving Samsung as one of the few remaining handset makers that is keeping it around.
However it seems that even Samsung could potentially be caving in to industry pressure because in a report from ETNews, Samsung is apparently planning on removing the headphone jack from future handsets, starting as early as the Galaxy S10 (which is set for a 2019 launch), the Galaxy Note 10 (also 2019), or the Galaxy S11 (set for 2020).
Instead what this means is that future Samsung customers will need to either find a set of headphones/earphones that come with a USB-C plug, or go wireless which seems to be the more popular option these days as more companies are creating wireless options. However the report does claim that Samsung is expected to include a conversion jack which we assume means an adapter/dongle of sorts.