Personally, I believe that an older, niche game should be extremely cautious about alienating their existing player base in the hopes of attracting new players. I just feel that the potential for a surge in new players is not very high; at least not enough to warrant chasing off existing players.
How is giving potential new players the option to get a pre-built ship for their chosen area of interest going to alienate or chase off existing players?
If existing players didn't engage with Engineering previously they can choose to continue to ignore it or get one of the packages themselves if they want to; it's still their choice. If they
have already unlocked Engineers then they will have access to better modules* than are available in the pre-built ships (and hopefully enjoyed playing the game while they were doing so).
Likewise with the Python II, existing players will either have enough ARX earned through playing the game already, be excited enough to spend money to get it sooner, or patient enough to wait.
*with the obvious exception of the G5 Dirty/Drag Thrusters in the AX Chieftain