'You will become part of my family now, and for all time, we will be brothers.'
Given how seriously Worf takes Klingon ceremonies and traditions, he would have followed through on the above statement.
But did Star Trek?
Is Jeremy ever mentioned again by Worf? In TNG, DS9, the films, or even in the books?
I don't think he has been, but would be happy to be stand corrected.
The character could have been a good intermediary between Worf and Alexander, but that opportunity was never used.
Great point in that Jeremy and Alexander would have a lot for an adopted family unit... it would be far better than what transpired with Alexander, not that it would take much. But, even if they were all one big happy family and not like the sarcastic way that Ramones song dawdles on about, they could still do cameos and one-off scenes and still remind audiences that the big bad flagship has kids aboard. Might take care of "Imaginary Friend", for those who dislike that episode - one that's clearly aimed at younger audiences, not unlike
Prodigy but without as much CGI. But I digress upon a digression...
But was Alexander addressed in the films? Nope. They're too busy fumbling around with action shlock and Picard clones and/or Borg drones that know how Picard does things running around.
Books? Unsure.
Standard TV fare; sequels are only brought up for what the makers think are the most interesting. In Startrekland, everyone ends up shiny happy, regardless if they grew up and escaped from rape gangs and stuff. Which is arguably the largest allegory Trek has ever made, but I digress, since that doesn't account for
the Cousin Oliver trope Alexander appearing out of nowhere and oh-so-tall and articulate by the age of three. It was inconsistent, but by season 5 they'd do anything for a soapbox.
But did the makers think Jeremy was worth following up on? He's doing well with his new adopted family. Naah. There's more drama out of Worf's direct family.
I'm sure Jeremy went to the academy and is an Ensign, being commanded by Sarjenka and the Horta, and off-hours they go have a BBQ with the Horta providing the lighter fluid.