[Note: the question's title asks generally whether Warping Implosion affects the user, but the question itself adds the supposition that the user teleported within the area of the damage effect. I'll try to address both.]
Warping Implosion (Generally) Does Not Affect the User, Because the User Has (Probably) Already Left the Affected Area by the Time the Damage Effect Triggers...
Critical to Warping Implosion is the fact that the force damage only triggers "after you disappear" and only affects an area around "the space you left . . . ." Logically, if you have left that space when the force damage triggers, you are no longer there and would not be affected by it.
...Unless the User Chooses to Teleport to a Space Within 30 Feet, in Which Case the User is (Probably) Affected...
As has oft been observed of 5e, there are no hidden rules. In particular, there is no hidden rule that a teleporting creature ceases to exist or to occupy any physical location, for any length of time, between disappearing and reappearing.
Anecdotally, my own experience at many game tables has been 100% consistent: teleportation means you cease to exist in one space and immediately begin to exist in another.
As far as I can tell, there is nothing in any official 5e resource published to date to suggest otherwise. A review of numerous teleport-type effects througout the 5e range confirms that none of them suggest any kind of pause or hesitation between disappearing and reappearing. In particular, I reviewed:
- the spells teleport, far step, misty step, thunder step, scatter, and word of recall;
- the Conjuration wizard's Benign Transposition and Way of Shadow monk's Shadow Step abilities;
- the Teleport abilities of a couple dozen monsters, from blink dogs to the demon lord Kostchtchie; and
- the teleport-type abilities granted by the astral shard and atlas of endless horizons.
Some of these abilities use descriptive words like "instantly" to modify the verb "teleport." Some don't. But none of them suggest there is any delay between disappearing and reappearing.
Of special note is the phase spider's Ethereal Jaunt ability:
As a bonus action, the spider can magically shift from the Material Plane to the Ethereal Plane, or vice versa.
The phase spider's lore entry clarifies that this ability resembles, but is not actually, teleportation: the spider
seems to appear out of nowhere and quickly vanishes after attacking. Its movement on the Ethereal Plane before coming back to the Material Plane makes it seem like it can teleport.
(Emphasis mine.) I read this to mean that it is the seeming instantaneousness of the spider's travel that gives the impression that the spider is teleporting -- but the travel isn't actually instantaneous, and the spider isn't actually teleporting.
Given the above, the best conclusion one can draw is that an Aberrant Mind sorcerer using Warping Implosion to teleport ceases to exist in one space and immediately begins to exist in another. Warping Implosion's damage effect also happens "immediately after you disappear," so if the space you choose to teleport to is within 30 feet of the one you left, you would be a "creature within 30 feet of the space you left" and would be affected by the damage.
...Except If You're Using the Optional "Simultaneous Effects" Rule from Xanathar's Guide to Everything, in Which Case the User Gets to Choose Whether to Be Affected.
Viewed as I propose above, Warping Implosion only cares about two time-states: (1) before you disappear, which is used to determine the space you will have left when you do disappear; and (2) immediately after you disappear, which is when both your appearance in a new space and the force damage effect happen simultaneously.
XGtE offers the following entirely optional rule for "rare cases" when "effects can happen at the same time":
If two or more things happen at the same time on a character or monster’s turn, the person at the game table — whether player or DM — who controls that creature decides the order in which those things happen.
If your table uses this rule, then the sorcerer's player gets to decide whether the damage effect or the reappearance in a new space happens first. By choosing to have the damage effect happen first, the player can choose to teleport to a space within 30 feet of the space s/he left yet still avoid the damage.