I think you should be fine. Automatic revalidation applies even when the nonimmigrant category changes, so a change in the I-20 details should be no problem.
See 22 CFR 41.112(d)(1)(ii):
(d) Automatic extension of validity at ports of entry.
(1) Provided that the requirements set out in paragraph (d)(2) of this section are fully met, the following provisions apply to nonimmigrant aliens seeking readmission at ports of entry:
(i) The validity of an expired nonimmigrant visa issued under INA 101(a)(15) may be considered to be automatically extended to the date of application for readmission; and
(ii) In cases where the original nonimmigrant classification of an alien has been changed by DHS to another nonimmigrant classification, the validity of an expired or unexpired nonimmigrant visa may be considered to be automatically extended to the date of application for readmission, and the visa may be converted as necessary to that changed classification.
(2) The provisions in paragraph (d)(1) of this section are applicable only in the case of a nonimmigrant alien who:
(i) Is in possession of a Form I-94, Arrival-Departure Record, endorsed by DHS to show an unexpired period of initial admission or extension of stay, or, in the case of a qualified F or J student or exchange visitor or the accompanying spouse or child of such an alien, is in possession of a current Form I-20, Certificate of Eligibility for Nonimmigrant Student Status, or Form IAP-66, Certificate of Eligibility for Exchange Visitor Status, issued by the school the student has been authorized to attend by DHS, or by the sponsor of the exchange program in which the alien has been authorized to participate by DHS, and endorsed by the issuing school official or program sponsor to indicate the period of initial admission or extension of stay authorized by DHS;
(ii) Is applying for readmission after an absence not exceeding 30 days solely in contiguous territory, or, in the case of a student or exchange visitor or accompanying spouse or child meeting the stipulations of paragraph (d)(2)(i) of this section, after an absence not exceeding 30 days in contiguous territory or adjacent islands other than Cuba;
(iii) Has maintained and intends to resume nonimmigrant status;
(iv) Is applying for readmission within the authorized period of initial admission or extension of stay;
(v) Is in possession of a valid passport;
(vi) Does not require authorization for admission under INA 212(d)(3); and
(vii) Has not applied for a new visa while abroad.
(3) The provisions in paragraphs (d)(1) and (d)(2) of this section shall not apply to the nationals of countries identified as supporting terrorism in the Department's annual report to Congress entitled Patterns of Global Terrorism.
See also 8 CFR 214.1(b)(1)(iv), which is specific to the I-20 requirement for F-1 students:
(b) Readmission of nonimmigrants under section 101(a)(15) (F), (J), (M), or (Q)(ii) to complete unexpired periods of previous admission or extension of stay -
(1) Section 101(a)(15)(F). The inspecting immigration officer shall readmit for duration of status as defined in § 214.2(f)(5)(iii), any nonimmigrant alien whose nonimmigrant visa is considered automatically revalidated pursuant to 22 CFR 41.125(f) and who is applying for readmission under section 101(a)(15)(F) of the Act, if the alien:
(i) Is admissible;
(ii) Is applying for readmission after an absence from the United States not exceeding thirty days solely in contiguous territory or adjacent islands;
(iii) Is in possession of a valid passport unless exempt from the requirement for presentation of a passport; and
(iv) Presents, or is the accompanying spouse or child of an alien who presents, an Arrival-Departure Record, Form I-94 (see § 1.4), issued to the alien in connection with the previous admission or stay, the alien's Form I-20 ID copy, and either:
(A) A properly endorsed page 4 of Form I-20A-B if there has been no substantive change in the information on the student's most recent Form I-20A since the form was initially issued; or
(B) A new Form I-20A-B if there has been any substantive change in the information on the student's most recent Form I-20A since the form was initially issued.