I have three right now that its time to get rid of as they do not fit our model nor do I want to take the time to continue to manage these (even with a PM).

Do you think it will affect the types of deals they pursue, or will the demand for flexible financing options like private lending continue to grow regardless?

They will continue to get 360 month loans for the 'cash flow'.

(Not that it's likely to be worth a legal fight I would guess.)

It can also be probably fight in court if this is a monopolistic practice if you think about it but who will want to fight it :D.  

From my own personal experience and from others I think most reach the "tipping point" from self managing to using a PM somewhere between 5-15  units, especially if you have a W2 and want to continue to scale. 

I hope my entry into real estate will continue this trend.

I’m continuing to invest in real estate while also helping others achieve their real estate goals.

You really do never know who is living next door...or driving down the street after having a fight with their wife, or....well you get the point. 

i would:-get the highest paying W2 job you can-save up enough to buy a house hack-house hackwhile you continue to learn and consider the other possibilities you mentioned.