We were reimaging some laptops (Dell) for redeployment (Windows 7, 64 bit). Instead of decrypting, I was told simply to login, disable Bitlocker, and then re-image the machine.

After the image finished and all installs were completed, I checked TPM (enabled/active) thru BIOS; however, when I went to enable BitLocker, it stated that TPM was either not present or activated - which is untrue.

At this point, I have cleared TPM - rebooted - still same error. I even tried tpm.msc and it said TPM did not exist. I updated the BIOS. 

What is the easiest way to remedy this situation? And, if there is a PROPER way of doing this (without having to wait for the entire drive to decrypt) I would greatly appreciate it.

Check whether the endorsement key get wiped out of the TPM after the re-imaging. This link might help you

MBAM fails to take ownership if Endorsement Key (EK) pair is missing

Another reason could be, that during re-imaging (maybe CM OSD?) there was Vendors TPM driver installed, and that is not supported By MS Bitlocker encryption. So check in device manager, if you have TPM 1.2 By MS or is it TPM driver By Dell/Lenovo/HP?