[[WMG: Bridge's full name is Bridget and Jack's is Jonathan]]
They're the only [=SPDs=] without a nickname. All their teammates have nicknames, and all their counterparts have nicknames. They can't be the only ones in SPD without a nickname.
[[WMG: The SPD become the Time Force]]
In Series/PowerRangersTimeForce, Bio Labs is shown to be reverse engineering Time Force technology, including the Quantum Morpher. Wes still has his morpher at the end of the series as well. It's likely that Bio Labs managed to reverse engineer a good amount of the equipment and help form the Earth-bound chapter of [=SPD=}, which also explains why Sky's father is wearing a Time Force uniform despite not being Wes: after the equipment was reverse engineed for function ''THEN''' the gear had its appearance changed to incorporate a new design. By the year 3000, we will have discovered the other ether technology.
[[WMG: Boom will become SPD Blue after the series]]
Yes, he washed out of the Academy, but he was able to put up a pretty good fight during the GrandFinale, and even in the pilot he was tossing around the three best students in the Academy. Odds are he was made a Ranger to replace the spot left by the retirement/promotions in the final episode.
[[WMG: The time traval turning people into a ball of light was total BS]]
* Sam's special power is that he could turn himself or others into a ball of light. He just chose to stay in the ball light form to screw with the other SPD rangers. That brief glimpse of him in his human form was basically him telling the rangers "Suck it" before heading back to his own time.
[[WMG: Other squad members got promoted.]]
After Jack's departure at the end of SPD, and Sky and Bridge's promotions, referenced in Once A Ranger, that leaves the core B Squad team with only three members (Bridge as Red, Z as Yellow, and Syd as Pink). Considering that their Mega Zords are designed with a team of five (or more) in mind, this would cause problems if they ever actually needed to take up their powers again.
They found SOPHIE again and she became B Squad's Green. When Sky and Bridge were promoted a second time, SOPHIE wasn't and they picked a cadet from C Squad to become the new Blue Ranger.
[[WMG: Nova is Z's daughter.]]
[[WMG: Grumm's horn was cut off during the final battle of Sirius]]
It would be the easiest way to connect the two of them, and the fact that Doggie escaped probably was a stain on Grumm's mind, hence his special anger at Doggie, and another reason why he considered taking over Earth such a priority.