Taking input from Kerala HC judgment here, Gujarat High Court held that, any agreement which has terms against to Public Policy, is void and not enforceable in law. Such agreements which prohibit right of maintenance are also void.

From Para 9,

9 In any case, all such issues are now well settled by few decisions of different Courts

[1] Rajesh R Nair v. Meera Babu reported in 2013 Cri. L.J. 3153, wherein Division Bench of Kerala High Court has held that waiver of right to maintenance by an agreement is not permissible because such agreement would be void agreement as against public policy. It would amount to ousting of jurisdiction of Magistrate and Family Court to entertain maintenance claim which cannot be permitted by law. Therefore, such agreement being void would be unenforceable and hence claim for maintenance cannot be rejected on the basis of such agreement of waiver of right to maintenance.
[2] In Rishikesh Singh alias T.R. Singh v. Kiran Gautam reported in 2015 Cri.L.J. 126, Chhattisgarh High Court has confirmed that decree of divorce obtained by mutual consent would be no ground to deny maintenance until wife has not remarried after divorce. It is further held that even if wife is junior advocate, it cannot be held that she is able to maintain herself and, therefore, she would be entitled for the maintenance.
[3] Smt. Vanamala v. H.M. Ranganatha Bhatta reported in [1995] 5 SCC 299, wherein the Hon’ble Supreme Court has also taken the same view that wife, who obtains divorce by mutual consent cannot be denied maintenance by virtue of section 125[4] and thereby restored the order of the Sessions Court, which has concluded that wife was entitled to maintenance notwithstanding divorce by mutual consent and remanded the matter to the trial Court for determining quantum of maintenance. Thereby, the Hon’ble Supreme Court has set aside the order of the High Court which held that wife is not entitled to maintenance once she has divorced her marriage by mutual consent. It would be appropriate to recollect here that for coming to such conclusion, the Hon’ble Supreme Court has relied upon as many as three other decisions of different High Courts, which are quoted in such reported case and approved by the Hon’ble Supreme Court. Therefore, as on date, there are at least as many as five judgments including judgment of the Hon’ble Supreme Court, which confirm that a wife who obtains divorce by mutual consent cannot be denied maintenance by virtue of section 125 [4] of the Cr. P.C.

Citations : [2016 SCC ONLINE GUJ 9136], [2017 AIC 172 524]

Other Sources:

https://mynation.net/docs/1095-2011/

https://www.casemine.com/judgement/in/5ac5e33e4a93261a1a744803