Unfortunately, yes. It is part of the checkride and if you don't finish it within the required time you will need to take the entire checkride again.
The commercial PTS shows the areas of operations that are included in the checkride, and the oral itself is given throughout the entire process. What most people consider "the oral" is the examiner asking questions during the "preflight preparation" portion of the checkride. This is where they ask the most questions because in all reality, this is where you as a pilot should be asking the most questions.
There is a note in the beginning of the PTS which talks about this:
The examiner conducting the practical test is responsible for
determining that the applicant meets the acceptable standards of
knowledge and skill of each Task within the appropriate practical
test standard. Since there is no formal division between the “oral”
and “skill” portions of the practical test, this becomes an ongoing
process throughout the test. Oral questioning, to determine the
applicant’s knowledge of Tasks and related safety factors, should be
used judiciously at all times, especially during the flight portion of
the practical test. Examiners shall test to the greatest extent
practicable the applicant’s correlative abilities rather than mere
rote enumeration of facts throughout the practical test.
As a small aside, you don't really get two months, but rather 60 days. This is covered in 14 CFR 61.43:
§61.43 Practical tests: General procedures.
(f) If a practical test is discontinued, the applicant is entitled
credit for those areas of operation that were passed, but only if the
(1) Passes the remainder of the practical test within the 60-day
period after the date the practical test was discontinued;
(2) Presents to the examiner for the retest the original notice of
disapproval form or the letter of discontinuance form, as appropriate;
(3) Satisfactorily accomplishes any additional training needed and
obtains the appropriate instructor endorsements, if additional
training is required; and
(4) Presents to the examiner for the retest a properly completed and