Let's consider the proposed particles that she lists in her article:
Since the 1980s, physicists have invented an entire particle zoo, whose inhabitants carry names like preons, sfermions, dyons, magnetic monopoles, simps, wimps, wimpzillas, axions, flaxions, erebons, accelerons, cornucopions, giant magnons, maximons, macros, wisps, fips, branons, skyrmions, chameleons, cuscutons, Planckons and sterile neutrinos, to mention just a few. We even had a (luckily short-lived) fad of “unparticles”.
All experiments looking for those particles have come back empty-handed...
This is a very mixed collection.
Giant magnons and skyrmions actually exist, as quasiparticles in condensed matter.
A preon is essentially any sub-quark particle. I think most lay people would consider this a quite reasonable concept, on the general principle that humanity has repeatedly discovered deeper layers of structure in matter.
A magnetic monopole would be a particle with "magnetic charge"; a dyon, any particle with both electric charge and magnetic charge. As concepts, these may also seem reasonable, given that we have electric fields and magnetic fields, and electrically charged particles that generated the electric fields.
Wimps are weakly interacting massive particles, a candidate for the dark matter that seems to have mass but doesn't otherwise do much; and wimpzillas, simps, wisps, and fips are all variations on this concept. Perhaps the names are not very dignified. But we could translate them as follows:
Wimp = dark matter particle that is massive but interacts weakly
Wimpzilla = dark matter particle that is extremely massive but interacts weakly
Simp = dark matter particle that is massive and interacts strongly
Wisp = dark matter particle that is light and interacts weakly
Fip = "feebly interacting particle" that may or may not be dark matter
My point is that these are all variations on the same hypothesis, "dark matter particle", with slightly different properties and parameter values.
A "macro" seems to be any larger-than-microscopic object that could constitute dark matter - it need not be a particle at all, and can even be made of ordinary matter, so long as it's dark.
Then we get to some concepts whose definition and motivation is a little more technical.
The axion was originally postulated to explain why the theta parameter of QCD is zero. Now it refers to a much broader class of possible particles whose exact definition is unclear to me, but which I suppose have a dynamics similar to the axion. Hossenfelder also mentions the "flaxion", which like all the variations on "WIMP", is still just an axion, but one that also does some other things (related to "flavor").
We know about three types of neutrino; a sterile neutrino would just be another one, one that didn't interact with any standard model forces.
Sfermions are supersymmetric partners of fermions. Not a very common word, compared to names of specific superpartners like squark, slepton, gravitino, and so on.
All those were a little technical, but still fairly common. Finally, we have a collection of rarer terms - erebon, acceleron, cornucopion, maximon, branon, chameleon, cuscuton, Planckon. (The unparticles are somewhere between "technical but common" and "rare", I guess.)
Anyway, what do we learn from this review? That the "undiscovered hypothetical particles" fall into some very different groupings. Some represent quite straightforward concepts ("sub-quark particle", "particle with magnetic charge", "dark matter particle"). Others represent concepts that are more esoteric, but popular with theorists, and which are considered well-motivated. Finally, we have concepts that represent highly specific scenarios that are only studied by a few people.