Philemon 1:22 - Not all prayers are answered in the way we would desire....

We really don't know the answer here..

Phm 1:22  But withal prepare me also a lodging: for I trust that through your prayers I shall be given unto you.

John Gill writes...

For I trust, that through your prayers I shall be given you; to minister in the Gospel again among them: the apostle was a man of prayer himself, and he had a very great regard to the prayers of others, and often desired an interest in them; that he might perform his ministerial work as it should be; that he might have success in it; and that he might be delivered from the unbelieving Jews, and from wicked and unreasonable men; and he had some secret hope and trust in his own mind, that through the prayers of the saints he should be delivered from his bonds, and go up and down preaching the Gospel as heretofore: he doubtless was acquainted with the case of Peter, for whom prayer was made incessantly by the church, when in prison, and he had deliverance; however, he knew that the prayers of the saints availed much with God; 

but whether this hope and expectation of his were answered, is a matter of doubt and question: some think he was released, and went into several parts, and preached the Gospel, and then was taken up again, and committed to prison, and suffered under Nero, some years after; and others think not.

As M. Henry's commentary states, this is not to neglect our duty.

(2.) Here is the ground of the apostle's request: For I trust that through your prayers I shall be given unto you. He did not know how God might deal with him, but the benefit of prayer he had often found, and hoped he should again, for deliverance, and liberty to come to them. Observe, [1.] Our dependence is on God for life and liberty and opportunity of service; all is by divine pleasure. [2.] When abridged of these or any other mercies, our trust and hope must be in God, without fainting or succumbing, while our case is depending. But yet, [3.] Trust must be with the use of means, prayer especially, though no other should be at hand; this hath unlocked heaven and opened prison-doors. The fervent effectual prayer of the righteous availeth much. [4.] Prayer of people for ministers, especially when they are in distress and danger, is their great duty; ministers need and request it. Paul, though an apostle, did so with much earnestness, Rom 15:30; 2Co 1:11; Eph 6:18, Eph 6:19; 1Th 5:25. The least may in this way be helpful to the greatest. Yet, [5.] Though prayer obtains, yet it does not merit the things obtained: they are God's gift, and Christ's purchase. I trust that through your prayers, charisthēsomai humin - I shall be freely bestowed on you. What God gives, he will yet be sought to for, that mercies may be valued the more, and known whence they come, and God may have the praise. Minister's lives and labours are for the people's good; the office was set up for them; he gave gifts for men, apostles, etc. Eph 4:8, Eph 4:11, Eph 4:12. Their gifts, and labours, and lives, all are for their benefit. 1Co 3:21, 1Co 3:22, All things are yours, Apollos, Cephas, etc. [6.] In praying for faithful ministers, people in effect pray for themselves: “I trust I shall be given unto you, for your service, and comfort, and edification in Christ.” See 2Co 4:15. [7.] Observe the humility of the apostle; his liberty, should he have it, he would own to be through their prayers, as well as, or more than, his own; he mentions them only through the high thoughts he had of the prayers of many, and the regard God would show to his praying people. Thus of the first thing in the apostle's conclusion.

Btw in case you didn't know it...

After the author's death, the work was finished (Romans through Revelation) by thirteen other nonconformist ministers, partly based upon notes taken by Henry's hearers, and edited by George Burder and John Hughes in 1811.^[5]