This is purely hypothetical, opiniated and full of questions.
Season 8 made huge strides to shorten the length of games. The updates incoming for pre season seem to further this agenda of rushing the game: Bosses such as Baron will spawn even sooner, and minions will be faster.
However, In contrast I think they are trying to make towers sturdier, and bounties more balanced, which I would think can only extend the game slightly.
My concern is for the scaling champions; the weak early game, strong late game champions. Season 8 already felt like a slight nerf to those champions. How will these champions fair in a lane against a strong early game champion in the pre season with stronger minion waves? Faster minions? Stronger towers? Even sooner spawning bosses? With the new rune setup?
Will these champions be safer because of the minion changes? Or will they be even more outdone in trades due to minion aggro? This of course would especially hurt those champions with no sustain in their kit. Will the faster minions mean more gold for these champions? Or would it mean that you will miss more gold when the early game bully your laning against forces you to back? Again, especially for those champions without sustain in their kit. Towers being stronger might help these champions, for a while maybe. But, once you lose the tower (if you do) and you are behind, does that mean that it will now be harder to get the enemy tower?
Season 8 changes were also tough on the junglers, giving incentive to playing stronger early game champions. Will reducing the spawn times of bosses and increasing minion damage (while ganking) hurt weaker early game champions much more than the latter? I'd argue that it would.
Is there any need for concern (do I have a point)?