Sorry, I have to correct you. This is completely false. Weight doesn't matter or affect guardians ability to use jump modes. Every jump mode in the game; Lift, glide, double jump, and blink, uses the Traveler's light to bend the users momentum, meaning they quite literally alter their bodies state of being and compliance with the laws of physics for a short time. The most complex jump ability and perhaps the one Traveler uses to flicker through solar systems on a grander scale, (Referenced in the Grimoire under allies: The Traveler) tears an impossibly brief hole in space time and exits at the other side. (Described in the Grimoire under Guardian abilities) Shoulder Charge is not a form of blink, it just accelerates the users velocity the way Double Jump does. It wouldn't matter how much a Guardian weighs. By using the Traveler's power, the user of these jump modes can counteract and at times, ignore laws of gravity and conservative mass (Light is infinite, is converted from no other energy and requires no input) Lore wise, Titans would 100% be able to use Blink. In game Class restrictions are the only reason they can't use it. You should also know that Titans were the first guardian breed raised by the Traveler and were around long before Warlocks, Hunters, and the last city.

Don't warlocks do the space teleport thing? But hunters just move really fast?

Where is this found in the lore?

I do not recall the exact location, but it is within the lore somewhere... I will need some time to remember, please understand... Until then, feel free to search for yourself.