Does the HD1 Quasar explain how Super Massive Black Holes Form? The galaxy HD1 has a 150M SM BH at its core.  HD1 formed SUPER early in the universal history.  It is 13.5B LY away (basically 330 M years after the big bang)...
So does this show that the clumpiness of the universe formed these early massive BH?
 A: The paper by Pacucci et al. (2022) is much more cautious in unequivocally attributing a quasar/supermassive black hole status to HD1; they suggest an intense starburst may be responsible for some or all of the brightness of this object (whose redshift is yet to be confirmed by spectroscopy).
If it is a quasar and it is accretion-powered, then the black hole mass would be $\sim 10^8M_\odot$. This implies very rapid growth of black holes (or at least this black hole) in the early universe, and more rapid on average, than is implied by the already-known $\sim 10^9M_\odot$ black holes in quasars that were present when the universe was only 700 million years old (e.g. Banados et al. 2018).
Given an exponential growth limited by the Salpeter timescale of $\sim 50$ million years, then black holes could grow by nearly three orders of magnitude in a 300 million year period after the big bang (if there were enough gas to keep this maximal accretion rate up). Confirmation of $10^8$ solar mass black holes at 330 million years after the big bang would certainly provide stringent constraints on the many proposals to explain these early-universe monsters. The predominant ideas are that this would likely require very massive seed black holes ($\sim 10^5M_\odot$), perhaps formed by direct collapse of the first very massive population III stars (Agarwal et al. 2012), combined with very high accretion rates and low matter-to-radiation efficiency. Alternatively, the seeds might be primordial black holes.
As Pacucci et al. (2022) state -

This black hole mass at z∼13 would require very challenging, but not implausible, growth parameters.

A: 
The galaxy HD1 has a 150M SM BH at its core

There have been other explanations suggested for the property leading to that idea and I don't think there's widespread agreement on the black-hole idea at the present time.
If you accept the result is correct then it shows only that the result is what it is.  It would take more examples to even began to draw conclusions as sweeping as you're asking about.  That's a general principle for science - you don't usually draw conclusions from isolated examples.
