The short answer is yes. The regional center's subsequent projects must fit the approved geographic area of focus and the approved "kind" of business as per the original application. If these or other significant details differ from what was outlined in the original I-924 application than an amendment must be filed.
A Regional Center Application as submitted to USCIS will include certain county or census tract designation (up to an entire state, and over state lines, if counties are contiguous), along with specific industry NAICS codes designations, which the RC is initially designated for and approved by USCIS. This is all included in a Regional Center Econometric Study, spelling out for USCIS the proposed economic impact area (geographical & Industry).
At anytime, after initial designation, a RC may incorporate additional projects, as long as they are within the geographic and industry designation. If they are outside the scope of the initial designation in either way, an amendment must be submitted with the new projects industry and/or geographic area.