For PvP, the Clipper will become obsolete.
Better shields, better convergence, better firepower, and roughly the same speed.
It's a shame they don't realize they can provide better PvP balance without disrupting PvE progression.
But but, balance? That would require communication with the community and actual work! No, that's definately not on the 10 year plan. Balancing is done via introducing new content based on bogo sorting algorythms until we have balanced the list of powerful ships and modules in the game.
On a serious note, balancing PvP will always uave an effect on PvE at some point. What is OP in PvP is most likely OP in PvE as well for example healing beams which can outtank whole CZs + capital ships.
FDev, however, rarely balances anything and only has done two balance passes since the release of the engineers back in 2.1. There is no way around doing regular balance passes (every 3 months is a good start) if you want to ensure a smooth and diverse gameplay in the game. The community gives proper feedback since years but next to never action is taken in time based in that feedback.
The Mamba will probably outscale the Clipper combat wise but only in combat. The Clipper will still be the fastest exploration and trading ship as it is a multipurpose ship rather than combat focused. It also has a higher MLF.
That said, the introduction of the Mamba and the Krait, however, will make everything obsolete that doesn't boost 550 m/s or more. Especially the big 3 suffer from this as their ToT will most likely be next to 0 and everything outruns their weapon range.
The new meta will most likely be speed and the connected ability to control engagements and dives. Right now, a fully combat fitted Phantom and Mamba boosts 610 m/s on a semi-lightweight build. Got a Python that boosts 480? Well, you won't hit anything.